I just put a new muffler on my wj 4.0 (magnaflow) and a boom tip and now my engine light is on any ideas?

 

Could be the little senor wasn't reattached..

 

It costs around a half hour of dealership or shop time to pull and clear codes. That's anywhere from $35 to $75.

I bought a basic code reader, Innova brand, and I check my own codes and clear them myself. I never have to guess and I can decide whether it is time to seek help or whether I just left my gas cap loose.

It was around $100, well worth the money. And if the code isn't in the book, just google it.

Jet

 

you dont need to buy any programmer/code reader, your WJ has it built in

just go to key on, off, key on, off key on and your code should pop up on the odometer.

go to http://www.wjjeeps.com/faultcodes.htm
and look it up!

 

The nice thing about having the reader though is that you can get info like if one of your o2 sensors is lagging behind or if an injector bank doesn't have enough pressure, depending on what model you have of course.

 

was it welded on without disconnecting the battery?