I checked the read before you post section and this wasn’t on it. I have an 07 5.4. Would it be a bad idea to cut my CATs off? The muffler and tips are already gone. I’m going for a deep loud rumble.

 

Your ECM won’t like it... you’ll need some fab work to keep your O2 sensors happy and possibly a custom tune.

 

It's an illegal modification that serves no purpose.

The cats already flow perfectly well unless they're compromised, in which case they should be replaced, not eliminated.

 

what if I’m going for a deep rumble? Regardless of the legal side?

 

EMC? I apologize I know like nothing, but am trying to learn.

 

Sorry, but there's no "regardless" of the legal side.

I'd invite you to visit a drive in circa 1970 to see firsthand why cats exist.

 

ECM...electronic control module...your truck's computer will not like not having something it needs to run properly...

Bill

 

Are you looking to straight pipe them? if so you need to do the non fouler mod. Look it up on google. I have straight pipe on one bank....it's a LONG story, but I eliminated the CEL by doing that mod. Truck has been running like this for years now with 0 issues. As for legality, that's on you, but I will say that loud will get really old, really fast. Better off getting a nice exhaust system than hacking yours up. Usually a nice muffler like a Flowmaster or Magnaflow does the trick for most people.

 

Pull the muffler, leave the cats. sounds like glasspacks.

 

I just cut a magnaflow off