my buddy just put a full aftermarket exhaust on his 05 lly with no lights on the dash. what percentage of trucks have the engine light come on due to no cat? it is only certain models like truck from california?

Only certain emission regions will set a light but most if not all will set codes.

It also seems like after it sets the code so many times it will hit the light. Finger stick it or wait for the new Predator. It is sussposed to overide it.

oteo125,

For non CA or other regions that have speical emmissions we see an approx 50% that will set a light if you add a full exhaust system that removes the cat. Do a cat back like our MBRP and see if it's what you need as far as EGT reductions etc, if not add the front pipe and then see if yoyu get a light. If you do then add the finger and egr plate. Call us if you have any questions we'll be glad to help you.

Mark @ DPPI

Where does one locate an EGR plate and the fingersitck? Also, can they be installed yourself with some basic mechanical knowledge and wrenching?

I was asked about this alot at Scheid this past weekend. Some see it some dont. Its a good question though.

i live in Cali and have no CAT and TTS Exhaust with no error codes

My 05 did not set any codes running open exhaust. None. California truck.

My guess is they modified the ECM program.

HOWEVER, our 04.5 did set EGR codes.

I just installed my complete exhaust less CAT and have been running for a week now and no codes or lights.