my friend has a 06 ss s/c with a gmpp exhaust. when he goes wot sometimes the car says engine power reduced and he has to pull over and restart the car cause it idles rough and stuff what could be causing this?

 

Check the code. Most of the time is a Tps code or throttle body code.

 

it sometimes does it and sometimes does.

 

Check wiring for freyed wires on fuel peddle, and also check wiring for throttlebody and make sure its clean if one is bad.replace

 

I had to replace my Throttle body because of this. Could be the cause. CHECK the codes that is what they are there for.

You can go to any car part place and the retards there will scan it for you, gladly. It is so that you will buy parts from them too.