Wayne Sumrall

I haven't looked but if my cat is a bolt on I am thinking of field dressing it for better air flow. Anyone with experience? And YES I know the laws!

I had a '99 SDuty w/cat that I operated on....incredible difference...then I cut the muffler off and straight piped it...beautiful sound.

Thanx

Mod (Ret.)

I've seen many cat's that were removed, hollowed out, then re-installed. Fools the "visual" test, but if you have a state that requires the "sniff" check, you'll fail. If you don't, then your answer is simple; remove it and have it replaced with a straight pipe. A muffler/exhaust shop can do this, but in some states they will require you to remove it, as it's against the law in most for a shop to do this and replace with a straight pipe. I'd do the straight pipe deal, that way you have your stock cat just in case you have to re-install it, or you decide to sell the truck and the new potential new buyer wants it. It's worth something, as thieves are hanging around dark parking lots and cutting them off; the metals used inside are good for the recycle salvage yards these days. Kind of like those that steal copper to sell that too.

You may end up with a check engine light on and a stuck engine code if you remove the cat; most of the engines these days have multiple O2 sensors, one on front of the cat, and one behind it to measure the oxygen/unburned gases. Some companies offer reflashed ECM/ECU's to override this. Check with some of the companies that offer "performance chips" and "tuners".
I'm betting that you will end up with a code if you remove or modify the cat. Just something to be aware of.
Another option is to buy a performance cat and install it. The performance cats on the market today flow better than the stock units. So if you're trying for some extra ponies, that may be a way to go and save on the ECM/ECU getting readings and setting codes.