Originally Posted by klebel
My guess is spark plugs. Are you still on original plugs? You should be replacing them every 20k miles at most with a tune. I just did mine. Then found out my coil packs were going bad too.
Right but I just tuned the car 2,000 miles ago. its 2011 335is with 25k that I bought when it had 23k.
The history shows a bad plug at 21k so I assume the car was tuned for a bit before it was traded back into the dealer. I actually flashed back to Stage 1 sport even though I have 93 available. The codes went away.
I agree the plugs probably were worn and the going to Stage 2+ increase the timing enough to have one fail. What concerned me were the other lamba codes, which is probably caused by the misfire but I was not sure.
I ordered a set of ngks one step colder, I'm going to give them a shot. From previous turbo cars I've owned the bosch always seems to wear out quicker.