rbblrsn said:Car: 2006 WRX Limited Wagon, 115K miles, stage 2 Cobb, Greddy 3" exhaust.
Condition: Car suddenly developed severe stumbling, misfire codes rotating thru cylinders.
Action: Started troubleshooting per Donkey's post, MAF cleaned, plugs replaced, etc. Found my problem during fuel filter replacement:
The plastic 1/2 of the twist-together filter canister in the in-tank filter had partially separated from the metal 1/2, and the O-ring was also damaged. Fuel leaked from the resulting gap upon pulling assembly, so I'm sure air could be sucked in also when tank was low or during sloshing from spirited driving. Replaced filter and o-ring, cleared codes and all seems well. There were no obvious signs that it had ever been serviced (lots of dirt on top of the tank) so this may have been a factory issue(??)
My suggestion for a Possible post update: "Check in-tank fuel filter canister for proper assembly and o-ring integrity to ensure fuel pickup is OK."
And what part of the first post did you read? Specifically the big letters in red..........My 03 wrx runs great with no problem but my check engine is still on and the code say all 4 cylinder is misfiring.and when i pound my car the check engine blink 3 times but still runs normal.
Let's go ahead and assume there are parts on there that are not stock or a mismatched tune. Can you identify them? It's quite possible you bought a used car that no longer has a custom tune on it, but may still have aftermarket parts. From dealer or private seller?Hey guys i need alittle advice yesterday I bought a 2008 wrx today I was driving and I had some check engine codes pop up p0304 cylender 4 missfire p0102 mass airflow circuit low Input p0113 intake air temp p0021 cam position timing over advancement bank 2 it happen at 1717 rpm I was just driving normal not all crazy and the check engine light started flashing followed by rough running and loss of power anybody ever experience similar issues or have any ideas on what it could be?
OK, new plugs, swapped coil packs around, but now I have 2 misfire codes. And, they didn;t follow the original #2 pack...Ugh.
ugh, originally a P0302, now P0303 and P0301
New plugs, new fuel filter, swapped coils as follows:
#2 to #1
#4 to #2
#1 to #4
#3 stayed put
And, it's not just a code since the engine runs bad like a misfire. How are the misfire codes detected by the ECU? Just a sensor for vibration, or is it some electrical test of each cylinder? In other words, how does it determine which cylinder to flag?
Is there a way to probe the connectors? I hate to throw $$ at parts.
Would a dealer/shop have any special tools that would make it worth the expense? or, would they just throw parts at it too?
Thanks y'all for the time and advice.