Silverado P0300 Misfire Code

For example:You have a General Motors vehicle and the Diagnostic Trouble Code is B0566. p0300 is a general misfire code, and p0301 is a misfire on cylinder # 1. This means that the on-board computer has detected that not all of the engine’s cylinders are firing properly. Table Of ContentsCommon SymptomsCommon CausesPossible SolutionsSolution #1 (YouTube #1)Solution #2 (YouTube #2)Solution #3 How To Fix Cylinder Misfires (P0300, P0301, P0302, P0303, P0304, P0305, P0306) (YouTube #3)Solution #4: Trouble Shooting A Misfire Code (P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308) (YouTube #4)TroubleCodes Diagnostic IdentificationRelated Posts: If you. I hooked up the OBDll reader and the code read P0300 which says it's a misfire. Silverado & Fullsize Pick-ups - p0300 random misfire - I have a 2004 silverado 2500hd with the 6. It has over cracked piller about mid way up. The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. The car had full power WOT but felt a little off down low. After reading and seeing what people have tried, I too went through a lot of those things. 2 Misfire Detected P0303 Cyl. Photo 1: The P0300 random misfire code might indicate a sympathetic cylinder misfire, which will disappear after the cylinder-specific P0304 code is ­repaired. Thanks in advance!. It is up to a smog check technician or mechanic to diagnose the components which might be causing an engine misfire. Chevrolet Code P0300: Random/Multiple Cylinder Misfire Detected. Some 2011-2013 F-150 vehicles built on or before 6/15/2013 and equipped with a 3. All of these issues can cause a P0300 code in the computer. Keep Christ at the center God Bless. The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. While driving up hills or increasing load, the CEL will flash multiple times, I pull over as I know CEL flashing is not good. at sometimes 48lbs but then holds around 55 at idle which is fine the problem!!! my truck is hard to start, have to give it a little gas. A P0300 diagnostic code indicates a random or multiple misfire. Hey, I have a 2000 GMC Sierra 5. A random misfire code usually means the air/fuel mixture is running lean. My engine has a miss, but it would occasionally go away (and so would the engine light). my check engine light came on with the code P0300 random misfire recently after changing my front cam seals to stop a oil leak, in the process of course as everyone knows i had to take off the timing belt to get to the cam seals. The P0300 code means that a cylinder (s) is misfiring or is randomly misfiring. The list of reasons for a misfire is quite long, so dropping off the car should be expected, as an answer might not be easily found. What is the cost to resolve a P0300? Estimated diagnostic cost = $100. P0301 means misfire cylinder #1, p0302 cylinder #2 and so on. A code P0304, for example, would tell you cylinder #4 is misfiring. Mainly the 5. A P0300 misfire code on a GM Silverado or Sierra may be caused by corrosion inside the ignition coil connector. The P0300 is a fault code which starts appearing when the car engine has a misfire which is not related to just one cylinder. I have a check engine light on for over two years. This article supersedes TSB 06-22-3 to update the Service Procedure. To check, use the scan tool to read for misfire codes or any diagnostic troubleshooting codes. Repairs: Bought a new fuel pump and installed it myself. anyone else seeing this problem? had it to the dealer 2 times and they cant come up w/ a reason for it. Some 2011-2013 F-150 vehicles built on or before 6/15/2013 and equipped with a 3. 7lt vortec silverado 2wd p0300 random multiple cylinder misfire Before everybody goes on a wild goose chase there are multiple TSB's for the code P0300. Truck ran perfect for 4,000 miles, now I have a P0300 random misfire. I've had it out since Saturday and it's ran beautifully. So I got a check engine light on my 03 silverado Took it to autozone and it read a P0300 which the guy told me was a random missfire that I could of been either wires spar plugs vacuum leak low fuel pressure etc. Read what code P0300 - P0308 mean and possible causes and repair. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. I just had the car tuned and I had them check the boots on the coils to. code went away for awhile and come back so i replaced the plugs and wires, cleaned the throttle body. The engine idle quality is poor. Of course when I brought it to the dealer the light was off, but I told them I got the code read from another local shop. Engine ticking or misfires seem to be happening on cylinders 1, 4, 6 and or 7 on the effected engines. 0 gas engine with 116,000 miles. It has over cracked piller about mid way up. Engine ticking or misfires seem to be happening on cylinders 1, 4, 6 and or 7 on the effected engines. 2003 Chevy Silverado 1500 LS 4WD 5. Trouble Codes › P0300. Had is scanned at Advanced, and they said it was a "Random Misfire. Then threw a code about the air recurclator valve. i tested the plug wires they were good. fault codes from P0000 to P0299 · Standard fault codes from P0300 to P0399 Chevrolet S10 (1995 - 2012) · Chevrolet Silverado Sierra (1999 - 2006). Mainly the 5. Hey, I have a 2000 GMC Sierra 5. I am getting a p0300 random misfire code and also a c0561-71, which I heard may come on due to the p0300. Or bad o2 sensor. Also verify the spark plugs are good. P0300 CHEVROLET Tech Notes The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. A random misfire means your engine is misfiring, but that the problem is not isolated to one or two cylinders. Symptoms: P0300 code-random misfire after an engine computer scan. Page 1 of 3: How to Troubleshoot a Misfire (GM 4. misfire on most cylinders. Ignition Misfire. It has been two P0300 misfire codes. Now P0300 being "Random" misfire, means that the control unit has not been able to pinpoint the exact cylinder or cylinders that is causing the problem, and if this is the only code this is also a general indication that the problem is intermittent. Start by checking for intake leaks, intake gaskets are a common caused of multi-cylinder misfiring. Once you have detected the problematic cylinder(s), check whether it's getting spark. Code p0300 engine is misfiring on #2 and #7 cyl at idle So far I have checked compression 155 & 160 switched coil, plug wire, plug and injector Checked fuel pressure 55-60 psi Checked egr Checked for plugged exhaust Changed both rear o2 sensors Compared all scanner data with another truck that is known to be operating properly. This is how to diagnose a code PO300 Random Misfire Code. When diagnosing a P0300 code, it is important to record the freeze frame information and then duplicate the code setting conditions with a test drive. fault codes from P0000 to P0299 · Standard fault codes from P0300 to P0399 Chevrolet S10 (1995 - 2012) · Chevrolet Silverado Sierra (1999 - 2006). Pay close attention to the engine load, throttle position, RPM, and road speed because a P0300 (which is a specific misfire) can sometimes be difficult to detect. Engine may stumble or miss Engine may be hard to start you may notice no issues Cause. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. Read what code P0300 - P0308 mean and possible causes and repair. Like we mentioned above, a P0300 code means that there's a problem that's keeping fuel from being burned in at least one cylinder, resulting in a misfire. Code samples. Misfire History starts over at "0" every time the. Check fuel pressure at idle and running speeds. Pencil Code is a collaborative programming site for drawing art, playing music, and creating games. (The term collective code ownership comes from Extreme Programming, although in the second edition the practice is called Shared Code. Fixed - Trouble Code P0300, P0171 and P0507 I failed the smog test today due to a whole bunch of trouble codes. P0300 - Cylinder Misfire Detected Random Cylinders. 5L Gasoline Turbocharged Direct Injection (GTDI) engine may exhibit various engine misfire symptoms accompanied by diagnostic trouble codes (DTCs) P0300, P0301, P0302, P0303, P0304, P0305 and/or P0306 stored in the powertrain control module. Also verify the spark plugs are good. Welcome! New users, welcome to codecombat discourse! As you know, this place is where you can ask for help, get hints on levels, share experiences that you had while playing codecombat, reporting bugs, etc. Misfire check showed heavy misfires in cylinders 1-3-5. On 6 and 8 cylinder engines, misfiring cylinder identification is disabled at high engine speed and only an general misfire fault code P0300 is stored instead of a cylinder specific misfire fault code (i. For weeks, I had codes P0133 (O2 sensor slow response, sensor 1) and P0140 (O2 sensor no activity, sensor 2), but the car was running just fine. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. I checked codes and found a misfire code for everyone of the six cylinders. The truck idles around 600? Seemingly low. Additional OBDII codes that are present along with misfire codes can shed some light on the cause. Im in the UK running FBO and Ecutek tune. FIXD explains symptoms, causes, and severity of code P0300. anyone else seeing this problem? had it to the dealer 2 times and they cant come up w/ a reason for it. Learn what does P0300 Chevrolet Cylinder Misfire Detected Random Cylinders means, location and how to repair? When a misfire occurs, engine speed will fluctuate. If i hold the revs at 1900rpm or more it misfires and the SES light flashes. 3 LC9 with code P0300 × Help us help you. Lots of people have various misfiring escapades here and there but everyone seems to have other weird symptoms and/or check engine lights going off as well. The CEL came back on again after a couple dozen miles. Have a 04 spec v that was a 1 owner car previous owner said it was had different cams put in by nissan and was driveing the other day and got a check engine light and of corse its the random multiple misfire code and ik alot of people say the main cause is a blown head gasket but its showing no signs of it wat so ever. Some Chevy Silverado owners with the 4. The second or third time it showed a misfire, the idle started to get worse. Cyl 1, 5, 6 and 8 showed a misfire even though the engine ran smoothly. When diagnosing a P0300 code, it is important to record the freeze frame information and then duplicate the code setting conditions with a test drive. p0300 is a general misfire code, and p0301 is a misfire on cylinder # 1. A P0300 is a difficult OBDII trouble codes to diagnose. the only code is p0300. Pay close attention to the engine load, throttle position, RPM, and road speed because a P0300 (which is a specific misfire) can sometimes be difficult to detect. Could this be. Start by checking for intake leaks, intake gaskets are common caused of multi-cylinder misfiring. 7L equipped pick ups and SUVs. Error Code P0303 is a common error code that indicates a misfire problem in the engine's cylinder, specifically cylinder #3. 3L V8 P0300 Misfire Code 1 Answer. I have a 1998 chevy Silverado and i get a trouble code of P0300 what is that and how do i fix it ? is causing the car to run lean and misfire. P0300 - Random Misfire. The code came back P0300 - random misfire. I have a check engine light on for over two years. Codes were P0300 and P0151 oxy sensor low voltage this time. Small stuff. It would run good cold but worse when warm or hot. Therefore with AFM (Active Fuel Management, formerly known as displacement on demand (DoD)). one gm tech advised using techron fuel injector cleaner but the chevy site says to use only gm upper engine and injector cleaner. A P0302 code, for example, would tell you cylinder number two is misfiring. I had a P0300 and P0171 code pop up last week and it was my O2 sensor on bank 2 sensor 1. However, that should show up as a code as well. It seems to only be one cylinder, but I haven't verified this yet. Replaced the coil ($50) and it solved the problem and runs great. Therefore with AFM (Active Fuel Management, formerly known as displacement on demand (DoD)). Ignition Misfire. I cleared the codes, but they returned within minutes of running the engine. By monitoring variations in the crankshaft rotation speed for each cylinder, the PCM is able to detect individual misfire. Engine size = 350 5. P0302 is a diagnostic trouble code (DTC) for "Cylinder 2 Misfire Detected". Edited February 8, 2014 by farago2r. Codes were P0300 and P0151 oxy sensor low voltage this time. p0300 is a general misfire code, and p0301 is a misfire on cylinder # 1. A P0300 diagnostic code indicates a random or multiple misfire. This is because another problem in the system may have caused the computer to throw a random misfire code. Code P0300 is simply a random/Multiple Cylinder Misfire. I got a code for a bad cam and crank senor. i replaced the o2 sensor but still have the p0300 code. When diagnosing a P0300 code, it is important to record the freeze frame information and then duplicate the code setting conditions with a test drive. P0300 sets when the control unit recognizes that one or more of the cylinders is not contributing, or working as hard as the others. Hour of Code December 2019. How To Fix P0300 random misfire codes in your car. anyone else seeing this problem? had it to the dealer 2 times and they cant come up w/ a reason for it. I have Googled and searched this site for my problem and I can't find anything. misfire on most cylinders. , P0301 - P0308). Tutorials and lesson plans for kids 8 and older. What Does Code P0300 Mean? OBD II fault code P0300 is a generic code that is defined as “Cylinder Misfire Detected Random Cylinders”, and is set when the PCM (Powertrain Control Module) detects either a random misfire on one cylinder, or multiple cylinders that misfire randomly. Code P0300: Random/Multiple Cylinder Misfire Detected. I messed with it for a month. Other than 1 they are all on one bank. Alrighty so I've replaced spark plugs twice, wires twice, coil, cap, rotor and distrubor, and have even gone as far as hollowing out the cat, It's a misfire code I can drive it for a hour and then all of sudden it runs like complete shit, it stalls(it's an automatic aswell) some times i don't know what else to do to it, any ideas on what it could be?. Symptoms of a Misfire. 【More than 15 Data】You will get more than 15 data from the detector, like Engine RPM, Calculated Load Value, Coolant Temperature, Fuel System Status, Vehicle Speed, Short Term Fuel Trim, Long Term Fuel Trim, Intake Manifold Pressure. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation. This article will help you to understand some of the most common causes of misfires and misfire codes (P0300, P0301, P0302, P0303, P0304, P0305, P0306, P0307, P0308) on the GM 4. Also verify the spark plugs are good. I was working on a 2004 msm (stock) that set a p0300 code after i changed the timing belt and water pump (i had the crank sensor off the car to do the job) and couldn't pinpoint what it was that was causing it and finally realized that the only thing that I touched during the job that could cause it (assumming no part had actually failed) was the trigger wheel and crank sensor. If i hold the revs at 1900rpm or more it misfires and the SES light flashes. Traditional document reviews are supported, as well as reviewing diffs generated by an SCM (Source Code Management) system and plain unidiff patches. ACNA Notices and Policies. P0300 sets when the control unit recognizes that one or more of the cylinders is not contributing, or working as hard as the others. anyone else seeing this problem? had it to the dealer 2 times and they cant come up w/ a reason for it. I cleared the codes, but they returned within minutes of running the engine. ones at about 2000 miles and now at 4500. What kind of codes are u getting. any ideas what else would cause a p0300 misfire. the car has 235k on the engine and has been well maintained with oil changes every 3k. ok i have a 2002 chevy silverado with a 4. " Kinda strange, because the truck runs flawlessly. I have an '04 KC and its been idling rough and the SES light stays on until I come to a stop where the truck starts idling even rougher and the SES light starts to blinkwell I got it home and after a couple hours, I tried to start it and it barely gave a cranknot even starting. Welcome! New users, welcome to codecombat discourse! As you know, this place is where you can ask for help, get hints on levels, share experiences that you had while playing codecombat, reporting bugs, etc. Additional trouble codes can shed some light on the cause. well I spent the day installing new iridium Bosh plugs, FUEL FILTER :(, PVC, and cleaning the air filter and system, and no changeI can now make the misfire happen on demandjust stay at 2400RPM or higher for about 20 seconds, and the check engine light starts flashing for the P0300 code. I have 55K on my 05. How To Fix P0300 random misfire codes in your car. Pay close attention to the engine load, throttle position, RPM, and road speed because a P0300 (which is a specific misfire) can sometimes be difficult to detect. 2005 Ford Taurus SE code P0300. Now this has been a problem on other forums I have been reviewing. Time for a daily "What could cause this trouble code" thread: My car: 2006 300c 5. A4 (B5 Platform) Discussion - Misfire Codes P0300 & P0301 2. The 2009 Chevrolet Silverado has 1 problems reported for engine misfire, bucks, shuts off. " Meaning, there are misfires in multiple cylinders of your engine. Read what code P0300 - P0308 mean and possible causes and repair. 2007 Chevy Avalanche 5. In the past 2 years I have changed out all 8 plugs and wires, fuel pump, fuel filter, mass air flow sensor, clea. I started experiencing a lower RPM misfire which was most prominent off of idle to 3k rpm. Another common problem on the older 350's that causes a slight misfire is a burned valve in the cylinder head. Most of the time a tune up will usually fix the issue. Also switched the coil pack from 1st and 3rd cylinder and still got the check engine light along with codes P0300 and C1242. If the engine misfires at idle and it's not an ignition coil issue or a lean problem, it is common for the valve to get tight and cause a rough idle with misfire codes. above idle #4 cylinder will misfire. I took it for a drive and on highway speeds, the engine responds well. 4 Misfire Detected Note: DO NOT diagnose or replace any components for the above faults before performing the update function as explained in this bulletin. I have a check engine light on for over two years. However, it doesn’t tell you the cause or solution. Additional OBDII codes that are present along with misfire codes can shed some light on the cause. 3L V8 P0300 Misfire Code 1 Answer. In the past 2 years I have changed out all 8 plugs and wires, fuel pump, fuel filter, mass air flow sensor, clea. car is not driven hard. You would normally start by checking your Chevy Silverado fuel trim with a scan tool. P0300 is a diagnostic trouble code (DTC) for "Random/Multiple Cylinder Misfire Detected". What kind of codes are u getting. Time for a daily "What could cause this trouble code" thread: My car: 2006 300c 5. Lean condition codes are causing your misfire codes. 1998 Chevy Silverado. IIRC 2,4, and 8 are on wires with the odd side directly on the plugs. code went away for awhile and come back so i replaced the plugs and wires, cleaned the throttle body. After a couple of days, the code cleared itself. It is always good to learn more. This is how to diagnose a code PO300 Random Misfire Code. Keeping good oil, and plenty of it. No change in the startup condition, but now the car misfired really badly on the highway. 0 gas engine with 116,000 miles. Subject: Engine Misfire/Tick Noise, Malfunction Indicator Lamp (MIL) On, DTC P0300 Set Models: 2015-2016 Cadillac Escalade 2016 Cadillac CTS-V 2014 Chevrolet Silverado 1500 2014-2016 Chevrolet Corvette 2015-2016 Chevrolet Silverado, Suburban, Tahoe 2016 Chevrolet Camaro 2014 GMC Sierra 1500 2015-2016 GMC Sierra, Yukon, Yukon XL. No experience required!. I tried to clean both again and drive the car around for a few miles in case it just needed to burn off some gunk, but after a while I got the codes P0300, P0303, and P0304. well I spent the day installing new iridium Bosh plugs, FUEL FILTER :(, PVC, and cleaning the air filter and system, and no changeI can now make the misfire happen on demandjust stay at 2400RPM or higher for about 20 seconds, and the check engine light starts flashing for the P0300 code. checked egr valve, not bad. at sometimes 48lbs but then holds around 55 at idle which is fine the problem!!! my truck is hard to start, have to give it a little gas. It is up to a smog check technician or mechanic to diagnose the components which might be causing an engine misfire. If no leak is found the next step is to replace the spark plugs. A P0300 diagnostic code indicates a random or multiple misfire. 3L z-71 V-8 4wd 70000plus kms my problem is i got a code which read P0300- misfire. This is because another problem in the system may have caused the computer to throw a random misfire code. SOURCE: my 2000 chevy silverado has Hi. 8 liter engine. With and Without Misfire Codes. GM has issued a service bulletin #PIP5147A to address a situation where you have a check engine light and retrieve trouble codes relating to a misfire. Cyl 1, 5, 6 and 8 showed a misfire even though the engine ran smoothly. Modular V10 (6. The truck runs perfect around town and on the highway but the misfire is relative to RPM. Chevrolet Code P0300: Random/Multiple Cylinder Misfire Detected. 1999 chevy silverado z71. For some reason it seems like the truck is erasing the PCM when the truck is off for a while. Some 2011-2013 F-150 vehicles built on or before 6/15/2013 and equipped with a 3. 2 Misfire Detected P0303 Cyl. I removed a spark plug wire and an injector clip in order to make the engine misfire and cause a P0300 code in the computer. A random misfire code usually means the air/fuel mixture is running lean. Pay close attention to the engine load, throttle position, RPM, and road speed because a P0300 (which is a specific misfire) can sometimes be difficult to detect. When diagnosing a P0300 code, it is important to record the freeze frame information and then duplicate the code setting conditions with a test drive. It is also a place to experiment with mathematical functions, geometry, graphing, webpages, simulations, and algorithms. 4 Misfire Detected Note: DO NOT diagnose or replace any components for the above faults before performing the update function as explained in this bulletin. Best to go back to basics. Check Engine Light On, P0300 Random Misfire Code. A P0302 code, for example, would tell you cylinder number two is misfiring. Hi just had to take my 2014 Silverado (with 6630 miles) in for an Engine Misfire ( according to On-Star). 2007 Chevy Avalanche 5. A P0300 diagnostic code indicates a random or multiple misfire. I am getting a p0300 random misfire code and also a c0561-71, which I heard may come on due to the p0300. What does P0300 code mean on a 2001 silverado? P0300 Diagnostic Code - Random Misfire Symptoms. Yesterday on the way to work my 2000 Chevrolet Silverado 1500 4WD with the 4. IIRC 2,4, and 8 are on wires with the odd side directly on the plugs. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. I knew the truck had the random/multiple misfire P0300 code but, his code reader didnt show the P0305 (cyl 5) misfire. The code came back P0300 - random misfire. p0300 is a general misfire code, and p0301 is a misfire on cylinder # 1. p0420 -Catalyst System Efficiency Below Threshold (Bank 1) P0463 Fuel Level Sensor Circuit High Input (is this the reason why my fuel gauge always is acting crazy?? some times when i have a 1/4 of gas in my car is always marking like if i have a full tank?? its just bouncing up and. Load test each ignition coil and see if one is breaking down intermittently. This article supersedes TSB 06-22-3 to update the Service Procedure. A P0300 diagnostic code indicates a random or multiple misfire. The commissioner is authorized to exercise all powers necessary to enforce the electrical code and the electrical code technical standards, including but not limited to the power to: 1. P0300 Random Cylinder Misfire. One faulty ignition coil can set all 6 misfire codes. It ran 'ok' but not the best, you could tell it was acting sluggish. Usually upon a test drive, I'll find it stumbling on acceleration. 2007 Chevy Avalanche 5. ones at about 2000 miles and now at 4500. OBD-II fault codes for ignition misfires are commonly displayed as shown below: P0300 - Random misfires; this is indicating that the engine management system is detecting misfires intermittently on multiple cylinders. If no leak are found the next step is to replace the spark plugs. A P0300 diagnostic code indicates a random or multiple misfire. Of course when I brought it to the dealer the light was off, but I told them I got the code read from another local shop. I had a p0300 code come up with a o2 sensor code so i replaced both upstream o2 sensors. Gage Data Out of Range. P0300 is a general and random misfire code, which means that the code is not going to tell you which cylinder is causing the misfire. Also switched the coil pack from 1st and 3rd cylinder and still got the check engine light along with codes P0300 and C1242. Break that up and you'll start getting some other fun codes. The truck has 88kmi. In the past 2 years I have changed out all 8 plugs and wires, fuel pump, fuel filter, mass air flow sensor, clea. White Smoke, Bad Smell, Misfire Code Help, Advice, Owners' Discussion and DIY Tutorials on S40 and V40. p0300 - Random/Multiple Cylinder Misfire Detected Truck is an 02 silverado with a 5. A partially clogged cat will also throw a P0300, you can do a basic check on it with a cheap vacuum gauge. I knew the truck had the random/multiple misfire P0300 code but, his code reader didnt show the P0305 (cyl 5) misfire. 【More than 15 Data】You will get more than 15 data from the detector, like Engine RPM, Calculated Load Value, Coolant Temperature, Fuel System Status, Vehicle Speed, Short Term Fuel Trim, Long Term Fuel Trim, Intake Manifold Pressure. Following is account of troubles: 1. But rather than just tune out the P0300 I took it seriously and logged everything misfire related. Unfortunately, a P0300 doesn't tell you specifically which cylinder(s) is/are mis-firing, nor why. P0303 is certainly a cause for concern, and can be a threat to the drivability the Chevy Silverado. GM has very common issues with their V8 engines. If the last digit is a number other than zero, it corresponds to the cylinder number that is misfiring. A P0300 does not point to any one engine cylinder nor does it explain the reason for the misfire. It idles great and drives fine if I baby it but as soon as it gets any load on it it starts to miss. After a couple of days, the code cleared itself. A P0300 diagnostic code indicates a random or multiple misfire. The P0300 code means that a cylinder(s) is misfiring or is randomly misfiring. 2007 Silverado 2500HD Classic, 182,000 miles, 6. Here is a list of things I P0300 misfire. Hour of Code December 2019. The car should be brought in for repair as soon as possible with the same day being ideal. It starts up and idles but when you give it gas it starts missing and backfiring. P0300: Random/Multiple Cylinder Misfire — What It Means. what does this code mean is wrong, my mechanic tells me it is likely to be coil or ECU as these are very common on fiat 1. The truck runs perfect around town and on the highway but the misfire is relative to RPM. Occasional misfires may pass unnoticed, but a steady misfire is hard to miss. Most of the time a tune up will usually fix the issue. Hey, I have a 2000 GMC Sierra 5. 3 My check engine light came on and I have these codes. A P0300 diagnostic code indicates a random or multiple misfire. The truck has 88kmi. 2 Misfire Detected P0303 Cyl. well I spent the day installing new iridium Bosh plugs, FUEL FILTER :(, PVC, and cleaning the air filter and system, and no changeI can now make the misfire happen on demandjust stay at 2400RPM or higher for about 20 seconds, and the check engine light starts flashing for the P0300 code. Learn what does P0300 Chevrolet Cylinder Misfire Detected Random Cylinders means, location and how to repair? When a misfire occurs, engine speed will fluctuate. checked egr valve, not bad. Alrighty so I've replaced spark plugs twice, wires twice, coil, cap, rotor and distrubor, and have even gone as far as hollowing out the cat, It's a misfire code I can drive it for a hour and then all of sudden it runs like complete shit, it stalls(it's an automatic aswell) some times i don't know what else to do to it, any ideas on what it could be?. But rather than just tune out the P0300 I took it seriously and logged everything misfire related. In this GM computer code, it should show a specific cylinder where the misfire is taking place. I cleared the codes, but they returned within minutes of running the engine. fuel pressure. If the engine misfires at idle and it's not an ignition coil issue or a lean problem, it is common for the valve to get tight and cause a rough idle with misfire codes. Usually upon a test drive, I'll find it stumbling on acceleration. I have replaced the spark plug wires twice, switched out the spark plugs with the five year AZ Delco plugs, cleaned the throttle body, cleaned the mass air flow sensor, checked the air filter and housing for obstructions, checked the PCV valve, checked for vacuum leaks. Hi just had to take my 2014 Silverado (with 6630 miles) in for an Engine Misfire ( according to On-Star). 8L V8 Vortec engine started flashing a check engine light. It has been two P0300 misfire codes. I have had a P0300 " random misfire " code issue for a few years now. It could be a bad coul. car is not driven hard. Symptoms of a Misfire. It can be anywhere from two or more cylinders misfiring causing this P0300 code to appear in the computer. Multiple Cylinder Misfire Detected Conditions. What Does Diagnosing the P0300 Code Entail? When your car displays a P0300 code, it means that you're experiencing a misfire. I would get an intermittent CEL which would produce a P0300 or P0308 code (random misfire or Cyl 8 misfire). This type of engine it is also a popular condition where the intake valve and the exhaust valve between those two valve develop a hair line crack on the number 2 cylinder. P0300: Random/Multiple Cylinder Misfire — What It Means.