2006 Saturn Ion
 

The reduced engine power light comes on randomly. What is the cause and how do I fix it? Took it to a mechanic, but they were unable to replicate the problem.

TPS ..... replace it

Read about the tps on the internet. You'll alot of info. Take a min and stop in the new member forum and give yourself an into. After that open the USER CP and add your first name, location, and car info.