Hi guys,
I just had truduals no mufflers put on my 07 1500 5.7. The last few days I'm getting the emissions light. Cleared the PCM and its coming back.

Any ideas??

Also o2 sensors & cats are still intact.

 

if you have to little back pressure that could set off the light because the 02s arnt working in the normal range.

if you have a scan tool what does it say

 

Do the "non-fouler" trick. It'll get the rear sensor farther off the flow and should eliminate the CEL. It's a common trick for those who cut out their cats, but should work for you too.
It's about a $10 mod and will take you about an hour to do. I did a DIY on it a while back, check the "DIY" section...