Hi All,

I have 2005 A4 with 51000 miles. The check engine light has been on, steady not flashing, as soon as the engine is turned on. Code detected is P0304 which is cylinder 4 misfire. First time reset the code, but came back after 200 miles of driving. Took it to dealership and he suggested the ECM software needed to be updated so got that done. But the code came back after another 200 mile of driving. Took it back to the dealership and this time they switched the ignition coil between cylinder 2 and cylinder 4. They did check the spark plugs and it looked ok to them, last had it changed at 35000 mile service. Now the code has come back within 300 miles drive and it still remains on cylinder 4 suggesting that the coils might be fine. Has someone seen similar problems or have any idea as to what else might be wrong. The mileage has gone down by 2-3 miles/gallon, always used 93 octane fuel. Other then that nothing obvious seems to be happening.

Any help would be appreciated,
Harry

 

ok so the code came back after they switched..... did the code change from p0304 to p0302....?


PM Me, i don't follow this forum much

 

the code still remained P0304 after the switch . Thank you

 

dude can be seal problem maybe leakeage into cylinder do your coils and spark plugs have oil on it ?