Dear everyone,


I just bought an RS4 B8 and I have a random issue.
At some cold starts, the car is having kind of misfire just for 1 or 2 minutes, and then everything works perfectly.
Misfire is really random whereas the fault codes are quite frequent at cold start.

If I move before approx 60deg celcius cooling temperature, I have also randomly an EPC light with 6500 rpm logo for 15minutes.
After everything disappear.

It appears to happen frequently when I move out my underground parking by climbing the hill.

De carbonization of the intake has been done 5 000km ago.
All the O2 sensor are new. Spark plug also.
I put a camera, catalizer is perfect (the cells).

I thought it could come from a defective 02 sensor but it seems that it’s not taken into account for rich balance before the cooling temp reach 60 deg Celsius.

So it should come from elsewhere.

I changed the Intake Pressure sensor (equivalent of Debimetre on CFSA engine.)

One time a got a ignition problem on 7 and 8 cylinder.
I plan to change de ignition coil.

Here are some screenshots of my logs if anyone has an idea.

Thanks a lot