Cat question - again - plz help
Thread Starter
Racer
Joined: Oct 2001
Posts: 304
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From: sometown new york
Cat question - again - plz help
My cats on my 99 are going bad. I've got the tell-tale corrosion around the fittings. The mods on my car are: LS6 intake, Blackwing, Powerduct (for looks), and GHL exhaust. The programming is stock. I don't whether I should replace the cats, or punch them out and use O2 sims. There is no emission testing in my area. They don't even look under the car or under the hood. :D I would prefer to use the sims, but I've heard about problems running sims on stock programming. Can anyone offer some "expert" opinions?
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Re: Cat question - again - plz help (connellyh)
Replacing the cats will be expensive and boring :( . If you can wrench a little why not take the opportunity to install a set of headers, offroad pipes, and xpipe? It might be as expensive as if you went to a GM dealer and had them replaced. They are welded in so they would probably put a whole new system in, for probably a little less than a header system and you won't have as big a smile on your face when you drive it. :D
Thread Starter
Racer
Joined: Oct 2001
Posts: 304
Likes: 0
From: sometown new york
Re: Cat question - again - plz help (ArKay99)
Yes, I would rather go with headers. I can't afford the $1k for good ones right now. I already have an X-pipe and good exhaust (GHL). Also, I'm still stuck with the original problem about O2 sims. As was pointed out in a previous post, I'll need LS1 edit and no one in my area has it. The closest place is Thunder Racing in Baton Rouge which is a LONG tow truck ride away and TR Edit time is EXPENSIVE. Add the headers, coating, the O2 sims, truck, and Edit time and the cost gets to $2k. Aftermarket cats, $500. Boring, yes. Will I regret it later when I put on the headers, yes. However, I don't want to ruin the exhaust system in the meantime. In the long run, I'm gonna loose $$$. anyway I do this. I would prefer to put in a pipe in place of the cats, install O2 sims, and reprogam. Which brings me back to the problem of no LS1 Edit access.
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Re: Cat question - again - plz help (connellyh)
TByrne has O2 sims for $89.99/pair and Thunder Racing has them for $44.95 ea., You need a pair. If you gut your cats and put O2 sims in, you most likely will not get any codes but you will have the 'unburned fuel stink' from a catless system until you get it tuned.
BTW, what would your dealer charge you to change out the h-pipe/cats? I know the assembly is pretty expensive, then there's that impeccable dealer labor...
If you pick up a Corsa Xpipe, I have the midsection I took off my 99 with cats. It's in pretty good shape and if you pay the shipping, I would send it to you for free. The only problem is they have been cut after the O2's to mount a Corsa Xpipe to them. Let me know. Actually I'd like to get them out of my garage. :thumbs:
BTW, what would your dealer charge you to change out the h-pipe/cats? I know the assembly is pretty expensive, then there's that impeccable dealer labor...
If you pick up a Corsa Xpipe, I have the midsection I took off my 99 with cats. It's in pretty good shape and if you pay the shipping, I would send it to you for free. The only problem is they have been cut after the O2's to mount a Corsa Xpipe to them. Let me know. Actually I'd like to get them out of my garage. :thumbs:
Thread Starter
Racer
Joined: Oct 2001
Posts: 304
Likes: 0
From: sometown new york
Re: Cat question - again - plz help (ArKay99)
What happens if I do get codes? My 91 would run like complete crap with an O2 sensor code. So bad, I couldn't drive it at all. I don't mind a code, if it doesn't affect how it runs.
I have an x-pipe and GHL exhaust in the car already. ...and no, I don't go to the dealer. Either I do it mysef (usually) or take it to a friend of mine's shop when I need the big toys to play with. Unfortunately, he doesn't have LS1 Edit.
Damn, I just need to find someone with LS1 Edit that charges a reasonable fee. One would think that wouldn't be too difficult. :banghead:
I have an x-pipe and GHL exhaust in the car already. ...and no, I don't go to the dealer. Either I do it mysef (usually) or take it to a friend of mine's shop when I need the big toys to play with. Unfortunately, he doesn't have LS1 Edit.
Damn, I just need to find someone with LS1 Edit that charges a reasonable fee. One would think that wouldn't be too difficult. :banghead:
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Drifting
Joined: Jan 2003
Posts: 1,389
Likes: 0
From: Raceland Louisiana
Re: Cat question - again - plz help (connellyh)
I have some 02 sims i can ship to you for 75 bucks. I also have the flp off road pipe to replace your cats, but it will probably need some fabrication on it to fit. The pipe has never been used and will sell that shipped for 50..
I'm pretty local too if you want to meet up somewhere.. I'm in raceland about 45 min away from the city..
I'm pretty local too if you want to meet up somewhere.. I'm in raceland about 45 min away from the city..
Drifting
Joined: Jan 2003
Posts: 1,389
Likes: 0
From: Raceland Louisiana
Re: Cat question - again - plz help (BayouVette)
and about an LS1 edit there is a guy Bryan Herter pcmforless.com Great prices. All you do is take out your pcm and ship it to him. Worked great for me.
The only problem is you dont really know if the edit took until you get it back in your car. This is what just happened to me. It was my second time for an edit. I got it for new gears, headers, xpipe, !cats and to eliminate codes. Got it back and it was no different.. :mad .. It through codes for no cats and shifts for the old gears.. So i had to send it back. Thats why I bought the 02 sims to get ride of the codes, but decided to put the cats back on.
The only problem is you dont really know if the edit took until you get it back in your car. This is what just happened to me. It was my second time for an edit. I got it for new gears, headers, xpipe, !cats and to eliminate codes. Got it back and it was no different.. :mad .. It through codes for no cats and shifts for the old gears.. So i had to send it back. Thats why I bought the 02 sims to get ride of the codes, but decided to put the cats back on.
Le Mans Master
Joined: Jan 2003
Posts: 6,298
Likes: 0
From: Tyler TX
Re: Cat question - again - plz help (connellyh)
Contact Thunder Racing and they can hook you up with LS1 Edit. They are located new Baton Rouge. They are a supporting tuner on this board. :cheers: :thumbs:
Thread Starter
Racer
Joined: Oct 2001
Posts: 304
Likes: 0
From: sometown new york
Re: Cat question - again - plz help (connellyh)
I've made a few more phone calls and finally got some answers. In my case, minor mods, O2 sims and "off-road" pipes will not improve performance. Yeh, I new that. What I didn't know was that on quite a few LS1 cars, the sims and pipes DECREASED power. :eek: Since I do not plan on adding any more mods in the next year, my best plan is to replace the cats.
Thanks to all that replied.
Buyouvette - you ever run the roadcorse at NPR? I haven't seen you out there. Are you going to the Vette/Viper day?
Thanks to all that replied.
Buyouvette - you ever run the roadcorse at NPR? I haven't seen you out there. Are you going to the Vette/Viper day?
Race Director
Joined: Aug 2002
Posts: 16,719
Likes: 1
From: Redacted
Re: Cat question - again - plz help (connellyh)
I suspect that if you hunt around, some one has a take-off H-pipe, complete with working cats that you can buy cheap.
Boring, but cleaner and a standard C5 h-pipe w/cats is probably as cheap or cheaper than any other solution, and it's a bolt-on replacement that you can most likely do yourself or relatively cheaply at a shop with a lift. They take less than 20 minutes to change out on a lift.
Boring, but cleaner and a standard C5 h-pipe w/cats is probably as cheap or cheaper than any other solution, and it's a bolt-on replacement that you can most likely do yourself or relatively cheaply at a shop with a lift. They take less than 20 minutes to change out on a lift.
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
Re: Cat question - again - plz help (connellyh)
I have an x-pipe and GHL exhaust in the car already. ...
Burning Brakes
Joined: Jun 2002
Posts: 1,055
Likes: 0
From: Troy MI
Re: Cat question - again - plz help (ArKay99)
I'm sure if you post in the parts for sale/wanted you can pick up a set of 02 or 03 cats cheap.
I bought a set of used TPIS headers last year for my '99 for $500, cut the cats off when I installed the headrs and brought the car to an exhaust shop with a 1.2' gap between my collectors and my H-pipe.
They welded in two new straight pipes for me for about $75.
I personally find it hard to believe that you would lose power w/o cats. Maybe if the tune is off because of it.
Do note that your exhaust will smell bad w/o cats. If it is a daily car that you drive to work, you may arrive smelling like exhaust.
I bought a set of used TPIS headers last year for my '99 for $500, cut the cats off when I installed the headrs and brought the car to an exhaust shop with a 1.2' gap between my collectors and my H-pipe.
They welded in two new straight pipes for me for about $75.
I personally find it hard to believe that you would lose power w/o cats. Maybe if the tune is off because of it.
Do note that your exhaust will smell bad w/o cats. If it is a daily car that you drive to work, you may arrive smelling like exhaust.