Sometimes when I start it after sitting for a while the car's check engine light turns on and the engine's RPMs randomly drop to 1000 RPM then goes up to around 2000. If I turn it off it goes away sometimes. It usually happens on wet days. Also, the system voltage is not low and does not change so its not like it needs to rev to charge it. The gas pedal does not move either. What should I look for? I didn't have a chance to look under the hood while its running since it does it on my way to school and not on the way home. Thanks.

 

That'd be my guess.

 

First thing I would do is find out what check engine code is coming up and start with that.