gutted cat

[RainierThanEver]

Howdy i recently took my truck (an 04 rainier wiht a 5.3) to a local exhaust shop wanting to see about getting some exhaust work done. i told em all i really wanted to do for right now was to get a muffler and have my cat gutted but the guy told me that they couldn't do that to my truck because it would make it run crappy? does this guy know what hes talking about or is he just full of ****?

[ShadowClutch]

Welcome to the forum!
Hopefully some other members will chime in, but from what I understand, these engines require a bit of backpressure. By gutting the cat and streamlining the exhaust, a good bit of the necessary backpressure may be lost.

If you can, take a minute to fill out your vehicle info in your profile so everyone can see what you're driving.

[pdutzel]

on some cars yes because it needs some back pressure.and i know in my state that is illegal for you and him ,something like a 1500 dollar fine

[shakin]

It will also start throwing check engine lights with the cat gutted.

[RainierThanEver]

alrighty thanks
do you know of any alternatives to gutting it? like a highflow of some kind that would be compatible with my vehicle

[joe70ss]

Did it my Monte Carlo SS,no problem

[wardak33]

you can try a test pipe in place of the cat. and if you do gut it or replace it, you can get rid of the CEL's with a PCM4LEss tune.

[WOOLUF1952]

Doesn't your state have inspections?

[RainierThanEver]

nope i live in pa
and i could deal with a check engine light i just dont want it to run ****ty

[bstromback2002]

The converters on these vehicles are pretty efficient and cause very little backpressure it wouldn't be worth it unless you were having problems and they were plugged. Get an exhaust backpressure gauge and check it you'll see what i meen you'll be lucky if it will even move the gauge at an idle and at higher rpm's you won't see much more that 2 psi of back pressure

[85vette]

There's no need to disable/strip catalytic convertors today. You can make plenty of power and torque and still stay legal (as far as keeping all the emissions equipment on the vehicle). Get a tune if you want more power than you have now.

[Wiseguyz]

my tb doesnt have one. 2 spark plug anti foulers worked fine to make the cel go way. just spaces the 02 sensor out and works like a charm.

[Valv]

If you want to get rid of your converters I'll be glad to take them away from you. My TB 5.3 just got 2 plugged ones.

Email me if you rather.

[CoyoteFireGuy]

I really expected to open this thread and see this...

[Chevy-TB-lover]

Thats pretty sick...
Get a tune, You'll notice a difference:m2:

[Irishboy02]

old thread but ill post anyways...

i kno our 4.2s require bakpressure but im not sure how the 5.3s handle it...if they dont require as much then this will give yu an improvement...idk how PA emissions are but if yu want to not worry get a magnaflow high-flow...they are a straight through pipe that basically just looks like a cat...will give yu a little bit more drone thoguh :m2:

[Foosh]

what he said:iagree:

[Jdub2010]

Old thread, but if I'm not mistaking our tb's have pre's and posts, and if there is no cat, it will be thrown in to limp mode, IF i'm not mistaking. Dunno much bout these Tb's yet, but ive delt with headaches on OBDII, but nothing a O2 sim wont solve. good luck.