Po302
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It means you have a misfire on cylinder #2. (P030X where X is the affected cylinder.)
P0301 through P0310 - Misfire Detection Monitor
The misfire detection monitor is designed to monitor engine misfire and identify the specific cylinder in which the misfire has occurred. Misfire is defined as lack of combustion in a cylinder due to absence of spark, poor fuel metering, poor compression, or any other cause.
Ignition system
Fuel injectors
Running out of fuel
EVAP canister purge valve
Fuel pressure
Evaporative emission system
Base engine
The MIL will blink once per second when a misfire is detected severe enough to cause catalyst damage. If the MIL is on steady state, due to a misfire, this will indicate the threshold for emissions was exceeded and cause the vehicle to fail an inspection and maintenance tailpipe test.
P0301 through P0310 - Misfire Detection Monitor
The misfire detection monitor is designed to monitor engine misfire and identify the specific cylinder in which the misfire has occurred. Misfire is defined as lack of combustion in a cylinder due to absence of spark, poor fuel metering, poor compression, or any other cause.
Ignition system
Fuel injectors
Running out of fuel
EVAP canister purge valve
Fuel pressure
Evaporative emission system
Base engine
The MIL will blink once per second when a misfire is detected severe enough to cause catalyst damage. If the MIL is on steady state, due to a misfire, this will indicate the threshold for emissions was exceeded and cause the vehicle to fail an inspection and maintenance tailpipe test.
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21,250 Posts
302= misfire on cylinder #2. This is not as urgent as a 316 that is misfire in the first 1k rpm, or misfire on cranking during startup. It does indicate that you've had more than one uh-oh in that cylinder.
To determine what the problem is- remove the affected spark plug. Inspect for deposits, note deposits, clean and re-gap plug. Re-install the plug. If you have lifetime warranty plug wires, then you should get a replacement immediately to cross that possible cause off the list. If you have expensive racing plug wires, then we can do a test later to see if you need to go chunk change on a new set- if the problem re-occurs.
Plug issues we're looking for are extreme lean or rich conditions, or burning. Rich conditions will look black and crusty, possibly oily. Lean conditions will have white fluffy deposits, tan deposits are normal, red is impurities in the fuel. Burning makes the sparking part of the plug look like a blued gun barrel on the porcelain which is actually micro fragments of the anode and cathode being burnt into the porcelain insulator around the center conductor (anode).
Now for testing expensive plug wires, tune your AM radio to a position where there is no radio station or static from a station. Start the engine. You should hear the engine through the speakers. Listen for rhythmic popping sounds. That indicates a spark "leak", and IMO you should put your expensive racing plug wires on the shelf for autocross or drag days, and go get you a lifetime warranty set at your closest parts store for daily driving. This way you can change plug wires any time you have any concern about the ignition system without costing you anything.
To determine what the problem is- remove the affected spark plug. Inspect for deposits, note deposits, clean and re-gap plug. Re-install the plug. If you have lifetime warranty plug wires, then you should get a replacement immediately to cross that possible cause off the list. If you have expensive racing plug wires, then we can do a test later to see if you need to go chunk change on a new set- if the problem re-occurs.
Plug issues we're looking for are extreme lean or rich conditions, or burning. Rich conditions will look black and crusty, possibly oily. Lean conditions will have white fluffy deposits, tan deposits are normal, red is impurities in the fuel. Burning makes the sparking part of the plug look like a blued gun barrel on the porcelain which is actually micro fragments of the anode and cathode being burnt into the porcelain insulator around the center conductor (anode).
Now for testing expensive plug wires, tune your AM radio to a position where there is no radio station or static from a station. Start the engine. You should hear the engine through the speakers. Listen for rhythmic popping sounds. That indicates a spark "leak", and IMO you should put your expensive racing plug wires on the shelf for autocross or drag days, and go get you a lifetime warranty set at your closest parts store for daily driving. This way you can change plug wires any time you have any concern about the ignition system without costing you anything.
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OH, I forgot. Clear the code from the PCM after cleaning the plug and replacing the plug wires- if needed- and then drive the car and see if the code reappears. It probably won't come back, but if it does, then let us know what information you gathered from your experience- deposits, plug condition, gap, new wires, etc. We can go suggesting testing from there to determine what the cause is.
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I'm seeing evidence of oil getting in that tube- is that correct? If so, then you need a new valve cover gasket, and a new set of plug wires. You can try cleaning the plug wires, but you might not get all the oil and crud residue out of it, and even cleaners will leave a conductive residue. In fact, that was one of my spark plug wire tests- spray some sort of soapy household cleaner Fantastic or Purple cleaner on the plug wires, start the engine at night, and look for sparks in time with engine misses. That's one way to detect bad plug wires. The AM radio method is just easier.
Did you clear codes to see if the DTC came back? What was your plug gap? I might also be seeing evidence of burning on the insulator- does that look like deposit buildup or scorching to you? It's difficult to tell from here. If you think it might be scorching, then you could need a new coil. Sometimes when coils go bad they allow high current spark instead of high voltage which scorches the insulator and causes misfire. My wife's van did that, I kept replacing the offending plug, and it would screw up again in less than a day until I replaced the coil. That one condition you'll know if you have it because you can clean the plug, re-install it, even install a new plug, and it will fail in the first day. New plugs with this coil failure condition will show scorching after misfiring- it will be more obvious than on the older plugs.
Did you clear codes to see if the DTC came back? What was your plug gap? I might also be seeing evidence of burning on the insulator- does that look like deposit buildup or scorching to you? It's difficult to tell from here. If you think it might be scorching, then you could need a new coil. Sometimes when coils go bad they allow high current spark instead of high voltage which scorches the insulator and causes misfire. My wife's van did that, I kept replacing the offending plug, and it would screw up again in less than a day until I replaced the coil. That one condition you'll know if you have it because you can clean the plug, re-install it, even install a new plug, and it will fail in the first day. New plugs with this coil failure condition will show scorching after misfiring- it will be more obvious than on the older plugs.
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ON second look, that seems more like just flat black rich deposits. Probably not scorching- that particular coil failure is rare. I worked on all sorts of cars I've owned and friends have owned for 20 years and didn't see it.
UPDATE so i took off the valve cover to see the gasket and i looked at it, it doesn't look like there's nothing wrong with it but i would like a second opinion on the gasket and is there suppose to be oil around the spark plugs here are some pics i took
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UPDATE so i took off the valve cover to see the gasket and i looked at it, it doesn't look like there's nothing wrong with it but i would like a second opinion on the gasket and is there suppose to be oil around the spark plugs here are some pics i took
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