[jon_335]

I mentioned this in an earlier rant post, but thought I would throw it out there as a specific post to see if anyone has had a similar experience.

The other day on startup, I had a surging idle, the car went into limp mode and was throwing P0221 and P0121 codes - throttle position sensor issues. I went through a process of turning it off and starting it up again several times and the problems persisted. As the engine warmed up, the idle calmed down, but still surged a little. And the codes were persistent.

The car is currently in the shop now. They reset the throttle response adaptations, which seems to have "fixed" it for now. If the problems come back, they are suggesting I might need a new throttle body. They tell me it could take several cycles to get the codes and surging idle again if it's truly a problem and not a random glitch.

I've owned the car for 2 years and have put ~15k miles on it. It currently has about 76k miles on it. The PO had a JB3 or 4 on it, but it didn't come with the car when I bought it. I've had very little problems with it over that time. In my searching, I've seen very little about bad throttle bodies or throttle position sensors on this car … mostly forum posts about the M3s and some 5-series.

Any thoughts on where to begin, without having to replace the TB? Clean the throttle body and MAF? Possible bad connections at the charge pipe, TB and intake manifold? Clean the sensors (if I can figure out where they are … maybe inside the TB)?

TIA!