gregowen

I have a 2005 E60 545i with the N62 V8 engine and about 140K on the clock. Recently I had issues of oil leaks and misfires so with the help of a really smart young guy who worked at the local indy shop I replaced the following parts with new & aftermarket ones:-


Two New OEM valve covers
Coils
Plugs
Upper Timing Cover Gaskets
Two new CCV pipes
The dreaded Alternator bracket Gasket
4 New O2 sensors


The difference was awesome after this was done but recently my Check engine light came on. I checked the codes and P2187 and P2189 appeared to be the culprit. This relates to mixture and so I reset the SES light thinking if it was bad it would reappear. For a while it stayed off but then came back this time with P0420 which i think is the secondary air supply and often the pipes under the intake that go bad.

Are these all related to something else I missed or are they even connected at all to each other? Any information would be much appreciated. I love the car but the high miles is giving me grief. I have new struts and wheel bearings to do next at the front and the transmission valve body to do also.