cats and exhaust

[01burban]

I'm cutting off my y pipe on my 2001 5.3L suburban and running dual 50series and i was wondering if i cut my cats out or gutted them would that make me gain more hp? i know i need a tune so c.e.l light wont come on and run like crap. but will it come on if i just gut my cats ? and also will there be a difference in power or mpg if i go dual exhaust?

also what are some not so expensive parts to gain more hp? i have a K7N c.a.i.

thanks

 

[tahoe7689]

there was an article I read a while back that said a high flow cat vs. no cat was maybe +1 hp for the no cat setup. I have high flow cats, that way i dont have a check engine light. but I do not have an exhaust, so maybe the exhaust would make a difference with out a cat. I can tell you my brother's silverado has no cats and an exhaust, and that thing is extremly loud! It also drones on the highway and can make some unplesant noises (maybe its just a crappy exhaust....he bought it like that so I dont know whats on it).
I think these trucks do need some backpressure (meaning you need cats), can someone clarify?

 

[rigo_jones]

get some high flow cats that way youll be legit and your truck will have a more of a deep tone than a loud farting tone depending on your exhaust. also you will get a CEL if you remove the cats but can be bypassed with some spark plug extensions or something like it. not recommended.

 

[tahoe7689]

you can get a dummy O2 sensor, which is what is sending the code and turning the CEL on. Or you can get a tune like you mentioned in order to turn that CEL off

 

[rgaffney]

so cats over an exhaust system?

 

[Max]

Stock cats flow quite well, no reason for replacing them unless you're gonna do longtubes or a turbo. These trucks aren't too stinky w/o cats but I'd at least do a high flow just to keep the smell down. You will not see any power or mileage gains from deleting the cats unless they are ridiculously clogged.

 

[rgaffney]

Would I fail an emmissions test if I decided to get longtubes?

 

[Rivieraracing]

Would I fail an emmissions test if I decided to get longtubes?

If they did a visual and saw that there weren't cats on your truck they would fail you, at least here in Oregon they would!

 

[rgaffney]

The test I did in GA last week was rather simple, but I'm still not comfortable getting anything just yet until I could find someone to give me a buddy emissions test and just give me a thumbs up pass

 

[Tahoe03mm]

in washington they don't do visuals and where i live no emissions... bye bye cats