Cats or no Cats? hmmm

[Telecaster5000]

I'm about to buy a 99 or 00 trans am, and the first thing I want to get is exhuast. I already know that I'm going to get a flowmaster cat-back system. I live in oklahoma where there is no inspection so I dont have to worry about that, but if I took my cats off would it make my 02 sensors go crazy? I basicly just want it a little louder then just catback, just need some pros and cons of cat removal thanks.

[Joe 1320]

If you remove the cats. you'll need 02 simulators for the rear two 02 sensors. They are the ones that are responsible for monitoring the effeciency of the cats.
(No cats)+(no simulators)=SES light.

Bresides that, cats have gotten pretty effecient as of late. Without them the HP gain is minimal and it will be pretty loud. The cats themselves make pretty good mufflers.

[Jay 02 TA ws6]

If all you want is a "little louder", then by all means, DO NOT REMOVE YOUR CATS...... especially if removing them would be part of a header installation.

LT headers + no cats + flowmaster = DEADLY LOUD.

Also, don't gut your cats. It can cause a raspy sound, and you may actually lose HP... either remove them, put on some high-flow ones, or leave 'em be.

My .02

[Injuneer]

Your Trans Am will have four O2 sensors... two before the cats to control A/F ratio, and they will not know whether the cats are there or not. Then there are two "after-cat" sensors, that monitor the efficiency of the cats. Remove the cats and you need to either replace the after-cat sensors with O2 "simulators", or you need to have the PCM reprgrammed to delete them.

I seriously doubt there is much in the way of HP to be gained by totally deleting the cats. Hollowing them out creates a hollow/raspy sound. A friend of mine with a 98 T/A replaced the "off road" pipes in his 3" custom Y-pipe with CarSound high flow cats, and picked up 2 mph.

[JeffM]

I gutted the cat in my 94 Formula and noticed nothing other than a sound increase. Seemed like it may have robbed a little torque too.

I say leave 'em be.

How about an SLP loudmouth exhaust. They sound nasty.

[fbodyj]

Leave the cats on. Why risk a violation for gaining no power.
Truthfully, you don't need to go that far with the F-bodies for
sound. A Flowmaster American Thunder Cat-back,Carsound
Cat and Cutout will make it loud enough!

[Brandon94za4]

My 94z28 with all the bolt ons, hot cam,headers, slp two on the left exhaust, and no cat sounded awesome. It wasn't too loud by any means. I used to get compliments on that thing everytime I got gas. I say kill the kitty. Get an off road pipe, don't gut the cat.
Brandon

[Jay 02 TA ws6]

Originally posted by Brandon94za4
My 94z28 with all the bolt ons, hot cam,headers, slp two on the left exhaust, and no cat sounded awesome. It wasn't too loud by any means. I used to get compliments on that thing everytime I got gas. I say kill the kitty. Get an off road pipe, don't gut the cat.
Brandon

Headers, no cats "wasn't too loud by any means"????

It is NASCAR loud.

[Brandon94za4]

What can I say I like loud stuff.
I say Nascar loud was when I opened the cut out. I couldn't run it all the time like that due to the fact that I think it was affecting my hearing
Brandon

[BAS]

when I had only headers on my car
in the garage, the car started up
so easy and sounded so raw and nasty.

I put the cat and borla on, the thing
definitely had problems breathing

it would barely start!

but on LS1, SLP loudmouth cat back
rules supreme

Originally posted by Brandon94za4
What can I say I like loud stuff.
I say Nascar loud was when I opened the cut out. I couldn't run it all the time like that due to the fact that I think it was affecting my hearing
Brandon

[fastTa]

Like the Injuneer said you can "delete" the rear O2 sensors with LS1 edit. That is what I would do considering it is approx. $75-$90 for a pair of O2 simulators and most "f-body familiar" shops I have talked to around here in texas will do a rear O2 sensor "delete" for about $40

[FireFinder20]

perfect...

Do you guys know where I can get a high flow cat for my 95 T/A? I just bought it Saturday, but the guy removed the cat, it's retarded loud and has that nasty rasp to it when i decelerate. Summit's doesn't work on OBDII cars...

[JeffM]

I gutted the cat on my 94 formula, and didn't notice a gain. Actually think I lost torque.. Just got louder.

I'd say leave it in.

[fastTa]

Re: perfect...

Originally posted by FireFinder20
Do you guys know where I can get a high flow cat for my 95 T/A? I just bought it Saturday, but the guy removed the cat, it's retarded loud and has that nasty rasp to it when i decelerate. Summit's doesn't work on OBDII cars...

Here are a couple:

Thunder Racing

Fast Toys
Scroll down for this one.

[FireFinder20]

Re: Re: perfect...

Originally posted by fastTA
Here are a couple:

Thunder Racing

Fast Toys
Scroll down for this one.

Thank you much!