Really hope this isn't a repost as i searched here and other sites all day and found nothing. Basically i have an 07 2500hd classic 6.0 4x4 and want to put headers on it. All ready set on the speed engineering ones. My question is whats the best way to keep cats in the exhaust system. Do you have to have the cats between 02 sensors as they are factory, or can you do the off road y pipe then a single cat, muffler, dump? Obviously that would require a tune which im doing with black bear. Just want to know if that would be sufficient. If not whats a good option for factory style dual cats.

Thanks.

 

You can do a single cat after the y-pipe if you want, two cats are not required. The cat(s) must be after the primary o2 sensors.

The rear o2 sensors can be disabled in the tune but I do suggest you leave them plugged in because some tuning softwares can not disable the cat test that can happen when the rear o2 sensor circuits are left open.