No it will not.....My has been deleted for over a year, and never once has it set a check engine light. There are no senors hooked up to the CAT. If your area requires diesel emission checking, you will fail the visual CAT inspection.

 

Deleting a Cat will not throw a CEL

 

sorry guys but you are all only half right... My late build 2004 throws a "p401" insuffient egr flow code after a few mins with egr delete.

heres the skinny: cat removal won't set off code as no sensors plugged in but with egr deletes its based on truck yr and split yr models...

2003- early 2004 it wont.
2004.5 (mine) -up it will more often then not...

if you don't want to run a horse power tune you can still turn egr off with just a trans tune. and you don't even have to adjust options. I just run 1. egr off, 2. better shift firmness, 3. adjust revs per mile setting for my larger tires.

just get an sct tuner with an egr delete. there have been cases where with an egr delete the cooling fan comes on much later and can run a hot engine esp while towing.

 

OP was asking about cat delete, not egr.

 

i have an 03 and i put on a 4" MBRP straight pipe no cat or muffler and every now and then i get the P132B code...im wondering if it is because of the larger diameter pipes and getting more exhaust flow without the back pressure...can the cat delete be the problem? Also my MPGs have gone down slightly.

 

haha yep just realized. sorry for making a fool out myself... Oh boy if i read as fast as i typed :look:


unless you hvae the dpf system you won't get a cel from a cat and or muffler delete. i go no muffler and a hollowed out cat and no check engine light except caused by egr delete.

 

Remove cat = no light.

 

I got a 05 no kitty no light