P0302 – Cylinder 2 -misfire detected
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Last Updated 2017-08-26
ASE Master Tech
| Trouble Code | Fault Location | Probable Cause |
|---|---|---|
| P0302 | Cylinder 2 -misfire detected | Engine mechanical fault, wiring, ignition/fuel system, injector, ECT/MAF sensor, ECM |
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What Does Code P0302 Mean?
A misfire is just what it sounds like; a cylinder that is not firing as it should. The P0302 code is caused by a misfire on the number two cylinder. The Misfire monitor diagnostic is based on variation in crankshaft velocity. The PCM determines this information using the crankshaft position sensor and camshaft position sensor. A misfiring cylinder slows down momentarily, so by monitoring the cam and crank sensor signals, the PCM can calculate when a misfire occurs. A P0302 code tells you only that a misfire has been detected, not WHY the cylinder is misfiring. That’s why with this code, a thorough diagnosis is mandatory.
Misfire Monitor
Different manufacturers implement OBD-II requirements slightly differently. The misfire monitor is an OBD-II procedure which identifies a misfire.
The misfire monitor is a “continuous” monitor; it is always checking the crankshaft position sensor for a misfire. It is important to note that the misfire monitor is very reliant on the crankshaft position sensor signal. A faulty crankshaft position sensor will misdiagnose misfires!
Ignition Systems
Waste spark distributorless ignition systems (DIS) are common on many cars. Identifying and understanding a waste spark DIS can help with troubleshooting a misfire.
Your car has a waste spark DIS if there are fewer coils than cylinders. The system shares a coil with two spark plugs corresponding to companion cylinders – the cylinders which are opposite in the firing sequence.
The following Youtube video series describes the GM waste spark distributorless ignition system:
More information on the other systems involved in a misfire can be found in the background section of codes P0300 and P0301.
What are the common causes of code P0302 ?
When you encounter a single cylinder misfire, the causes of systemic misfires such as: fuel pumps, EGR valve leaks, or crankshaft position sensors are less likely. Individual spark plugs, fuel injectors and valves should be carefully examined for the cylinder. For companion cylinders, the cylinder noted by the PCM may test fine. Be sure to check its companion in the firing sequence. For a P0302 code, the causes could be:
- Cylinder #2 Spark Plug
- Cylinder #2 Coil
- Cylinder #2 Wiring
- Cylinder #2 Fuel Injector
TIP: Check for a technical service bulletin. There could be a known repair for a single cylinder code. Sometimes the PCM is wrong.
What are the symptoms of code P0302 ?
A single cylinder misfire can be accompanied by stumbling or lack of power. The car can also run fine.
How do you troubleshoot code P0302 ?
Often, the best way to troubleshoot a single cylinder misfire is to swap ignition components between the misfiring cylinder and a good cylinder. If the misfire moves with the sparkplug (for example) then the sparkplug would be the cause of the misfire. If switching components to a good cylinder doesn’t eliminate the original misfire then there could be a problem with compression. See articles P0300 & P0301 for in depth troubleshooting of the four misfire causes: fuel, spark, timing, and compression.
BAT Team Discussions for P0302
- Misfire... Need help badly.
Hi guys. I have a 2002 Mitsubishi Galant ES 4cyl AUTO. ~127k I have done all the maintenance and more. Beginning at like 75K, the car started shaking at idle when in drive. at like 120K, timing belt broke and was brought into a NOOB shop. No bent valve. No damage. Though now, the car's engine sounds... - 97 Nissan Quest Checking Engine light on - 2nd Cylinder missing fire
97 Nissan Quest, 95K miles. Suddenly the check engine light went on. Went to Autozone and the scan showed "2nd cylinder missing fire". The error code is P0302. Then found the wire to the 2nd cylinder was "leaking fires" - the rubber insulation was broken and some fires went the metal holder of the w... - Code P0302
I have a 1996 Ford Windstar 3.8.Ck engine light on. Scanner shows P0302, misfire on #2. I replaced the spark plug & wire on #2 but after driving light comes on again. What should I look for? Thanks... - 03 MITSU GALANT
[quote="Jim Fairbanks"] If you can get the code # and post it back here it would help a lot. . . . Jim [/quote] code is P0302 MISFIRE #2 CYL i did a rough inspection there is power going to injector, i swapped plugs with #2 #2 has a coil pack on top of that one.... - 99 Cougar problem...HELP!
Depends on what is wrong with the cats exactly. If the cats are restricted, then yes it WILL cause a misfire and blinking check engine. However, you should also have some misfire fault codes in here. You are sure you saw the check engine light "flash" or "blink"? If so, there was a misfire detected....
Hey guys I have a 2005 Cadillac SRX AWD V8 with 3 misfire codes registering with obd2 P0301, P0302, and P0308. Is there any chance with this many codes registering misfire and a reading that shows 11 problems and a second obd that registered 16 problems, that maybe the firing order has been changed by mistake or improperly set prior to buying this vehicle now owner of 1 week.
My codes are as follows
P2176 throttle actuator control system – idle position
P0521 engine oil pressure sensor / switch range / performance
P2100 throttle actuator control motor circuit / open
P0420 catalystsystem efficiency below threshold bank 1
P0430 catalystsystem efficiency below threshold bank 2
P2097post catalyst fuel trim system too rich
P0171 system too lean bank1
P0174system too lean bank2
Do you think there is a good chance I only need to redo the firing order.
Responded to on BAT: http://www.batauto.com/threads/2005-cadillac-srx-reposted-from-troublecodes-net.15250/
2002 Jaguar S Type 3.0L intermittent misfire when accelerating on cylinder 2 .. this model year seems to have 2 different cylinder numbering schemes, #2 can be left front or right center, not sure how to tell, replaced coil on front right, no real change, next step is to remove intake manifold and replace plugs, coils and valve cover gasket .. any way to tell which one is actually 2 ?
Hey guys! I could use some help here. I have 2012 Subaru legacy. My check engine light came on and is flashing along with the cruise control and brake lights. There were 2 codes P0302 and P0304. Cylinders 2 and 4 misfire detected. I changed all 4 plugs and coils and no luck. I also checked all 4 fuel injectors and they checked out to be OK. My next plan of attack would be the MAF sensor. I unplugged it while the engine was running and it tried to shut off but it kept running. Not sure if that means the MAF is bad or not. I was going to check the voltage coming out of it but my multi meter died. Does anyone have any suggestions? Thank you for your help!
Subaru forester, 2009. Often stumbles when cold. Changed plug and wire. No change. Any ideas?
Olá pessoal tenho um ford fiesta rocam 2011, passei meu scanner obdII e apresentou esse problema, alguém conseguiu resolver? Qual foi o serviço? E foi caro? Podem me chamar no whatsapp 71 992274367, ou me mandar um email: [email protected]