Cat delete

[Haystack23]

I’m really debating on punching out my cat and running a straight pipe through it. My truck puffs out a cloud of white smoke when I dump it and I can tell a loss of power. Has anyone straight piped a 6.0? What are the pros and cons of doing it on a 2006 I’ve always done it to my older pickups but I’m not sure how it will affect this one 

[David89GMC]

Just remove the CATs and see how it works. You can always put them back if it makes no difference. CATs are restrictive, but not especially so on the street. Keep in mind that there are two O2 sensors on some of these trucks, my '03 has one before the CAT and one after the CAT. These are used by the computer to optimize the tune. Remove the CATs and you'll mess up that part of the tune.

My guess is the truck will run poorly without the CATs.

[sharkeysierra]

In theory you will free up more power, just buy a de fouler for the second sensor and you will be good, stinky but good.. 

[riverbanks]

Figure out the puff of smoke from exhaust,worn valve guide seals?leaking head gasket?I like clean air,if by diagnosis,one of the cats is bad,get another,and these post cat o2's are for emissions related problems,no influence on "tune",some Asian rides do

[CamGTP]

You'd want a tune done to stop all the check engine light codes. The non fouler trick might not be enough.

[sharkeysierra]

You don’t need a tune to keep the CEL off. 
 

a $15 defouler will do the trick... it has to be one to fully pull the sensor out exhaust flow (not short).