I was driving to work this morning like usual and I downshifted like usual when coming up this hill and it my engine felt like it lost power or i had to much weight in the car when you have a lot of passengers, but it was only me. I didn't have a bad shift or anything and then my service engine light came on. Still on all the way to work, but the car sounds fine. I'm not sure what it might be you think I should have it checked out and if I do should I take off my intake and put back on my cat? These are my mods.

Intake
Test Pipe
Exhaust

I didn't have any A/C or defroster on because I know you lose power when those are on I'm really confused on this one I looked under the hood nothing seemed wrong and nothing smelt bad LOL. Can someone help?

 

take it to autozone and check the codes for free, they will let you know whats going on.

OH and check your gas cap, make sure its tight sometimes that will throw the check engine light too.

 

really the gas cap? how so? wouldn't some gas be coming out if it wasn't closed tightly?

If was an internal problem would autozone still be able to tell if somethings wrong?

 

If a check engine light came on they will be able to tell you what the code is...could be all sorts of things.. The gas cap thing is a possibility..no, gas wouldn't go spewing, just make sure it is tight enough to make the clicking noise...

 

My CEL came on once after not clicking the gas cap down a couple clicks. Luckily the dealer only charged $45.00 to hook it up to the diagnostic machine to make sure that was the cause.

 

The gas tank has this thing where gas can get in but can't get out. You have to turn your gas cap until you here three clicks... if not you are letting air into your tank, and this will give you a check engine light... it has happened to me twice, but mitsu fixed my problem
Autozone will only check your car if your check engine light is on... they will tell you what the problem is for free

 

its your test pipe

 

why would it be his test pipe? can u explain? cuz i'm curious too

 

A test pipe could make the computer think the cat is blown out (because, hey, it's not there anymore is it?). However, here are some other things to consider if the car is running fine and the CEL is on.
- vacuum line slipped off (simple)
- gas cap (reduces fuel pressure)

moving to trouble shooting.