[CWarrior]

So over the past couple of months I have been having a code pop up, but only when going WOT, P0341, which gives me an "engine malfunction - reduced power", if I restart the car it fires right up, and the limp mode goes away.

I changed the spark plugs and found some oil in the cylinder 3 tube, cleaned it out and changed the plugs - car ran smoother, but still had issues at WOT. Independent mechanic told me that it was probably my valve cover gasket, but I show no other signs of leak, and I can see where oil dripped from my oil filler into cylinder 3 spark plug well, so that seems to be the issue there, not a leaking gasket (or am I wrong?). The car idles, runs and drives great, it just seems that when I push it the code pops up, one time, I had P0340 in addition to P0341 but it only happened once, I also had a couple long starts which threw P0341 code, but cleared on restart. I am leaning towards replacing the coils now, but does anyone have any suggestions or things I should check prior to putting those in? I kind of figured if it was a spark issue I would throw a misfire code, and if it happened to be the camshaft position sensor that it would continue being an issue, or the code would stay on if the CPS was really bad.

Any advice or recommendations would be appreciated. I have been searching and don't seem to find any issues that match my exact issue.

[CWarrior]

Sorry, forgot to mention the car is an 08 BMW 335xi. Could this be a symptom of my turbos not making enough boost? My waste gates sound horrible, and I'm well over warranty period. I also do not have a BT cable, but just a normal OBDII scan tool, is it possible there is a different code present if I were to find someone with a BT cable to scan it?

[CWarrior]

Ended up being a small break in the SIDE in one of my coil packs (not the boot, at the top), hard to see and have never seen that issue before, but replaced it and back at 100% incase someone else has these issues. Funny I never got misfire codes, just P0340 and P0341. At 140k miles now, and this has been the biggest issue that gave me trouble (other than noisy turbos and water pump / tstat repair).

[CWarrior]

I saw the small crack, put my thumbnail on the edge and it chipped a piece of the plastic right away, to reveal a tiny spot of rust. I put dielectric grease over it and tested it like this before installing a new coil pack. With just the grease covering it, it solved the issue (but I still replaced it as that is not a permanent fix). (Dielectric grease is NON conductive, before anyone yells at me)

I feel like I am talking to myself, but hopefully when someone else searches they will find this thread and fix their issue

[BashShah]

Our cars are well known to miss fire and not throw a code.

Good find, and you are not speaking to yourself.

DN

[CWarrior]

Thanks for the tip. I put a meter on them, and they all showed similar at idle. Will remember that for next time something comes up, plan to keep this car for a few more years, has been quite the daily driver.