I just got my car back on Wednesday, and I have had the CEL pop up 4 times now. One time the car was being driven a little hard, the others it was just regular driving (and when I say regular, I mean shifting at around 5-5500 RPM's). One time it was in neutral while I was letting it cool down. What would cause this issue, and should I take it back to my tuner?

 

What is the code for the cel? You need to know that to begin diagnosing.

 

Check all sensors and wires. if not pull the code delete it and if it come up again there is something wrong.

 

This will help in narrowing down to almost exactly why the CEL is being triggered.