my Audi A4 is running Rich at idle


The 47 Ronin
I replaced MAF, Coils and Spark Plugs = still same shit :(

1) High Pressure Fuel Pump

2) PCV, I saw wet oil/fuel on one of its corner

3) O2 sensor

Take your pick and Help me guys!! @tuc0


The 47 Ronin
Check your O2 Sensor first but have you checked your AFR to see what its reading on idle? If its reading low it might be your PCM dumping fuels. Have you noticed any blue smoke blow by?


The 47 Ronin
Thanks guys!

O2 sensors will be next...Since I saw the leak at the PCV, I have ordered one because I have to fix that leak anyway.

I have a reader and it said my O2 sensors are "OK" on its screen.