Qblue92

I have a "friend" who has eliminated the cats from his '92. I'm pretty sure that this will flow better than a hollowed out cat, but how much? there is a spare set of pipes with legit cats around here.. should "he" hollow them out and run them all the time, or leave them alone and install them just for state inspection?? :blueangel:

ZAD54

If "he" has to go through inspection I would put the gutted cats on. Gutted cats can't cut the flow that much, and it has to be better than keeping the cats on or changing them every year before the inspection. But thats just my opinion. :cheers:

EvanZR1

Replcaing the cats with a straight pipe would be the best solution. Leaving the gutted cats there will cause turbulence in the airflow path and will also often cause sound issues that can include rattling (if there is anything left inside) and resonance. Trust me on this, I had a "friend" that did the gutted route on his LT1 Formula and wished that he had replaced it completely or left it alone.

Corvette0096

kkonen

If your friend needs cats for emissions visual inspection. He might want to take a cat, cut it in half and reweld it on a straight pipe. Although the nice thing about vettes is that you can't see under the car unless it is on a lift.. :D

I have heard that the high flow cats don't hurt power that much if you have emissions testing in your state.

Togo

i hollowed mine out last week and have noticed a considerable improvement in performance! as far as rattling and noise, the only noise i now hear is the sound of the L98 breathing like she was meant to breathe!
in Az, you need to go through inspection only every 2 years, so i will eventually remove the pipe and replace every 2 years with a legit cat just for inspection! :cheers:

Skippy Stone

Are we talking removing everything from the cats or just the screens?

vader86

removing all the internal stuff

vader86

I would just gut them and put a straight pipe thru it, so you can have them for visual inspections. If you just gut it w/o puttin a pipe in, youll prolly have resonance problems.

Skippy Stone

Thanks

[/QUOTE]I would just gut them and put a straight pipe thru it, so you can have them for visual inspections. If you just gut it w/o puttin a pipe in, youll prolly have resonance problems.[/QUOTE]

Good idea.

snake killer

If you gut them won't you have O2 sensor problems? Don't you need those o2 readings in order for the computer to determine the fuel/air mixture?

GusBustamanteJr

I cut them out and put straight pipes on all 3 cats- great improvement, but VERY LOUD and the resonance is deafening. I now am considering a Power Effects system or putting a high flow cat.

Skippy Stone

The O2 sensor is in front of the cats. No effect.

Keep killin' those snake! :smash:


[Modified by Skippy Stone, 5:11 PM 7/5/2002]

FASGLAS

I understand a straight pipe through the cat shell would satisfy a visual inspection, but wouldn't fool the sniffer probe we have here. :mad