u/onyxandsaga

I have a 2011 Volvo S40 T5 throwing codes ECM-850D, 9200, 921D, and 922D. I recently replaced the throttle body and drove about 100 miles with no issues, but today the codes came back and the car went into reduced engine performance/limp mode.
While it was in limp mode, I was stopped with my foot on the brake and noticed the RPMs were fluctuating between 1000–2000 on their own. I shut the car off, restarted it, and it drove normally again for about 15 miles with no issues.
Has anyone experienced this or have any ideas what could be causing it? Wiring, ECM, or throttle adaptation issue?

I have a 2011 Volvo S40 T5 throwing codes ECM-850D, 9200, 921D, and 922D. I recently replaced the throttle body and drove about 100 miles with no issues, but today the codes came back and the car went into reduced engine performance/limp mode.
While it was in limp mode, I was stopped with my foot on the brake and noticed the RPMs were fluctuating between 1000–2000 on their own. I shut the car off, restarted it, and it drove normally again for about 15 miles with no issues.
Has anyone experienced this or have any ideas what could be causing it? Wiring, ECM, or throttle adaptation issue?