I just recently had a cat back system installed 3" pipe with a flowmaster on my 2002 F-150 4x4, 5.4 Lariat supercab. About 3 hours after I had this done my "service engine soon" light came on and I was wondering if this was because I had the cat back done and the computer detected a change or something like that.

About a week later I installed a FIPK F&N Generation II air intake and when I hooked the battery back up the light was gone but again it came on in a few hours. I was just curious if this was a common thing because I really don't want to take it in to the dealer and get raped for something simple. I do plan on getting a superchip tuner for my truck as well and if I remember right it can clear the service engine soon light but I won't be able to swing that for another month or so. I guess you can say I'm parinoid about this light so any help would be great.

Worried in Idaho.

 

I bet it has something to do with your rear O2 sensors.

But to be sure, go to AutoZone and have them read the codes for you. Then you can search for the code here on the forums, if nothing comes up there, post em on the forums.

 

Ok, that's what I will do and thank you very much for your help.

 

No problem