Cold Air Intake/Service Engine Light

Can someone please help.
I have a 2003 GTS Eclipse. I installed a cold air intake system awhile back and all was good, no probs. Now I'm having probs after having a bypass valve installed. My rpms jump around like mad on a cold engine and yesterday I had to restart my car 3 times and now the Service Engine Light is on. Can anyone relate or help me out?

I read back on some old posts and so far i've gotten this info:
1) Check all fluids
2) Check gas tank lid
3) Check Temp sensor
4) Reset ECU (not sure if that applies for Mitsu)

Thank you

Wrong forum, but is your MAF plugged in?

Sorry, whats a MAF?

MAF = Mass airflow sensor (I think). On the 2g's it is a large black plug attached directly behind the intake. I don't know about the 3g's that's a different forum. Take the car to autozone and have them scan the code. They will do that for free.

Oh yeah, the MAF is definately plugged in.