02 buick rendevous/rpms racing

My rpms keep going up and down without giving gas. When i put it in park the rpms go up to over 2000. Now I shut the car off before putting it in park.

Probably the IAC motor or valve.

A Haynes manual should help you here.

I am in agreement with mountainbike.
Have your mechanic focus on the IAC and he will probably find the source of the problem.

Finally got it fixed today. It was the TPS. Throttle Position Sensor

It was the TPS. Throttle Position Sensor