Hi,
i just bought a 2006 3.0 Automatic Subaru Legacy EDM.
The CEL light is flashing and I get P0301, P0303 and P0305 codes: Misfire for all cylinders of bank 1...
and P0172 system too rich bank1
It runs fine when cold, but when the temperature increases, after 10 minutes drives, the CEL flashed and the car starts to drive rough, the idle is unstable, it shakes.
We replaced all 6 spark plugs, the coil from Cylinder 5 (the one that had the most misfire errors), switch the front AVCS valves, replaced the rear AVCS valve with the one from a 2nd car, exchanged the front O2 sensors.
when working on the car, I noticed that the previous owner emptied the catalysators....
I wanted to connect ECU flash and get the ROM, so I looked for the green connectors but they were already connected: we were driving with the connectors connected.
(On my 05 spec B, when they are connected the fuel pump is cycling and CEL is blinking)
So I disconnected them and tried to drive again, then the P0420 appeared. and it disapeared when the connectors were again connected...
I suspect the ECU was modified to avoid the P0420 CEL when connecting the connector. I am tryiing to get back to the original ROM, we will see if it is possible.
I am also thinking about an injector problem, I will get them cleaned.
Would you have an idea what else could cause a misfire on all 3 cylinders from bank 1?
the spark plugs where also very strange when we replaced them:
cylinder 5 and 4 were like new the ceramic completely white and clean
Cylinder 3 and 2 were completely black
The 2 other where "normal": clear ceramic and metal but with signs of combustion
Thank in advance
Guillaume