Theman

Hello everyone. I'm trying to fix my mom's car. She has a 2009 C300 4matic and it's been having various driving and idle speed issues. I'll list them in Chronological order as these happened in about a 3 month period.

1) The idle speed in park/neutral would climb very high, well past 1500 rpm all the way sometimes to 3k, generally happened when warm. Restarting the car or putting into drive would take care of it. Tapping the pedal only added to the engine acceleration.
2) The idle would bounce around 500 rpm, bouncing between 500-700 rpm when warming up but would go away once you drove. This happens when cold.
3) While driving, the car would sometimes hold an engine speed without pedal input. I could be driving down a road at 40 mph and it would keep going w/o cruise control. Hitting the accelerator pedal or braking would take care of the issue.
4) The car would downshift from 2nd to 1st at a stop and it would turn off esp and go into limp mode, this threw a P061 code and was wiped by restarting the car until I came to a stop again/downshifted from 2nd-1st.

I suspected the TPS and was right. I purchased a remanufactured throttle body, installed it yesterday and got rid of 3 and 4 but am still having issues with 1 and 2. Anybody have any ideas on what it could be?​