Check Engine light after muffler install???

[89stang10sec]

Would having a set of single chamber flows put on my 01 gt cause the service engine light to come on? I had them installed yesterday and everything was fine then when i started my car this morning the light came on. Also, single chambers sounded awesome on my 5.0 but they sound like crap on my 4.6, what are your thoughts on the mac catback?

 

[rustang04]

they might of left something unplugged though they shouldn't of had to unplug anything. mufflers won't set a cel

 

[bdcardinal]

go to autozone and get the code pulled. mufflers shouldnt alone set off a MIL.