Renegade

iTrader: (1)

Well after a really annoying rattling underneath my car for the last week I finally had it checked out while getting my car aligned and it sounds like the cat is falling apart, I've experienced a clogged cat before on one of my friends cars so I'm going to get it taken care of.

The local exhaust shop said they couldn't just remove the cat and do an off-road Y because it would mess up my car and be illegal. Although I know a ton of people have done it, and it would be cheaper than replacing it with a high-flow. I've also considered just replacing it and installing a cut-out... my exhaust is really quiet right now with just a Magnaflow muffler and I'm looking to get it a bit louder.

Basically my options are go to the shop, have him replace the cat with a hi-flow for $225 installed, then have him put on a cut-out, probably manual since I will probably like and never wanna cap it anyway. Or if I should just find someone who will do a custom ORY and put a cut-out on anyway.

Any advice and opinions will be appreciated, either way my car won't have as many annoyances lol.

98Z28MASS

iTrader: (6)

Why not just unbolt the y-pipe and gut the stock cats? Only thing is you will probably throw an ses code. If you have a shop make a custom ory you will need front 02 sims and also you will have to have the code deleted as well.

Renegade

iTrader: (1)

That actually sounds like a pretty good idea, wasn't thinking about just gutting them. Would it be more beneficial to gut them and just leave them as is or would it be better to put a straight pipe through the cat so it appears to have cats but is just straight through... or putting a cut-out somewhere?

Also does anyone know how much not having cats would effect my car's performance, have any mechanical related issues, I'm not wanting to remove them if it's gonna cause problems, from my experience it will just not be able to pass emissions which isn't a big deal at this point.

98Z28MASS

iTrader: (6)

It would be the cheapest option and would def give you a few extra ponies as the stock cats dont flow that well at all. Gutting the cats wont cause any mechanical issues, you just will probably throw an SES code. A custom ory might flow slightly better but will probably cost you approx $100-$150 from my experience.

98camaroLS1M6

iTrader: (35)

my 98 passenger cat gutted itself after breaking up and shooting out the back.
Yeah, I would just gut what's left.

BlackScreaminMachine

iTrader: (17)

Gutting the cat creates turbulance, not ideal for making power plus you get a really annoying backfire type noise when you are on the decel. Depending on the cat, if you can put a straight pipe through it, it would be most ideal, and looks legal.

You could get a after market y pipe setup with cats, random tech makes one, OR find a friendly shop to fab up the y pipe.

Renegade

iTrader: (1)

Thanks for the advice, I really appreciate it. Would you or anyone else recommend having a pipe welding through the middle and just leave the cats for appearence rather than just gutting them and leaving them there?

BlackScreaminMachine

iTrader: (17)

Look at my prev post, we may have crossed posts, that is what I was thinking but I dont know how the 98's CAT's looked like. LT1's you could do that.

Renegade

iTrader: (1)

Yeah we did cross paths on that one, I was originally considering just the ORY rather than a catted one as I don't want to spend the money on cats unless I really have to, the SES Code is no biggie I'm always throwing them anyway. But I might check into some pricing on a ORY from a shop.

lsx24

iTrader: (45)

I would get a set of Magnaflow ceramic core high flow cats, about $50 each, and have them weld them in there. Cheap and legal. Shouldn't hurt flow very much if at all.

Renegade

iTrader: (1)

Thanks for all the info guys, I've recieved a lot of good suggestions. The Hi-Flows are also a good option which I've considered, right now I'm not really sure what I'm gonna go with, I'm leaning towards gutting the cats and having a pipe put in so I don't have to mess with cats but would pass a visual inspection. Plus I like the way exhaust usually sounds without cats, with my magnaflow it should sound even better than just putting hi-flows in with a cut-out, keep the suggestions coming and once again I appreciate the feedback, will be having the shop do something in the next day or two.

98Z28MASS

iTrader: (6)

If you gut the cats you shouldnt have to put a piece of pipe in the cat unless you want to elimate the cats all together. I gutted my mac cats and had no issues. Clip in sig is with my 232/238 cam, mac mids, gutted cats, magnaflow.

stonie97

iTrader: (5)

Not sure what years this was good for, but check w/ your dealer on a recalll for the cats. vMy passanger side broke down and plugged mine at the Y so I went ahead and gutted them the rest of the way and bought some o2 sims off another board member . I recieved the notice in the mail about two weeks after it happened. they replaced them. I have a 2000 SS, but the recall was good for any vehicle equipped w/ the 5.7l

justin quick

iTrader: (5)

I have QTP headers and the QTP Catted Y pipe along with a Magnaflow catback and a few months after i installed the exhaust all the crap that was in the cats blew out threw my exhaust when i was in a street race. I recently put the same exhaust on my new 02 SS and there isnt a damn thing left inside the cats. I havent had any problems at all with them being gutted. When it happened i didnt really notice any horse power loss or gain just sounded a hell of a lot better with a little more rasp.

Renegade

iTrader: (1)

I didn't buy my car from a dealer or anything but I will definitley stop in and check and see.

As for the other comments, if I'm going to be gutting them I have come to the conclusion that a pipe going through creates less "turbulance" than just leaving the cats and it's just pushing through a pipe rather than a large area if they were to be gutted, I really like the way the cars I've heard have sounded with the cats gutted or gone so I'm leaning towards this option if I can get a shop to do it, or if I'm just gutting them rather than putting pipe in I could probably pull it off myself.

Is the turbulance thing really that big of a deal where a pipe is beneficial, I'm not that familiar with cat's considering most of the cars I've dealt with have been older carburated vehicles lol.

Renegade

iTrader: (1)

I think I'm gonna go into the shop today and talk to them about gutting the cats and running a pipe through, if they won't do I'm gonna attempt to pull it off myself, have to find a welder to borrow lol. Thanks for all the feedback guys, made the decision much easier and gave me more options incase this one fails.

98Z28MASS

iTrader: (6)

The turbulance that the exhaust gases would have going through a hollowed catalytic converter is minimal and I dont really see a need to put a piece of pipe running inside the cat as it will probably restrict air flow unless it is the exact same diameter as the rest of the piping going into and out of the cat. I would say it wouldnt be worth the money to have them cut apart your stock exhaust to put pipes in side of the hollowed cats for maybe a few ponies. Just take you stock exhaust off, grab a crow bar, and smash away everything inside your stock cat and be done with it as the rest will blow out over time.

Cakes

iTrader: (1)

I had a similar problem on my '99. My passenger's side cat was rattling. I got it replaced for FREE at a dealer under warranty. There is an emissions warranty for 8YRS/80K for emissions equipment. All I had to do was call and make an appointment and I had it back the next day. You may want to try that if money is tight. My driver's side is beginning to rattle and if it gets too bad before my long-tubes I am going to do the same thing.

If you want to go the "Y-Pipe" route and do not want headers, Stainless Works makes a bolt on catted y-pipe and off-road style that will bolt to the stock manifolds. Hope this helps.

Renegade

iTrader: (1)

98Z28MASS: Thanks for the info that's about the same thing the exhaust guy had told me, considering I work 50 hours a week I'm just going to pay the exhaust shop to gut those cats for Me although I could probably pull it off if I have the chance, but I hear what ur saying just gut them.

Cakes: I've spoke with our local GM Dealer and they said they haven't heard of anything like that, my car only has 72k on it so I figured something would be able to be done like you said but it's looking like I'm SOL.

I suppose I will atleast get louder exhaust out of the deal lol.

Cakes

iTrader: (1)

Renegade, its time to find another dealer. Trust me it exists. I just spoke with a buddy of mine who bought a 2000 SS new and he recently received information on the cats and their warranty was extended until 100K. Here is a link to the original warranty document but like I said I think it has been ammended. Seriously I did not pay a dime and I got a brand new cat no questions asked.

http://www.epa.gov/otaq/consumer/warr95fs.txt