Because my 3rd gen is considered historic here in NJ, I no longer need to worry about passing emissions. I'm looking to remove the catalytic converter and replace it with a test pipe or something like it. Anyone know if they have one made out there that I can purchase with flanges on each side?

 

I got one from this guy on Ebay


bourque7-77

 

can you provide me with a link?

 

https://m.ebay.com/itm/CONVERTER-TES...AAAOSwVFlT9MA-

Look at the description to see if it will work. If not send him a message

 

Yes that is the one I got and it fit fine for the single cat system.
Thanks for finding the link, it was over a year ago I bought that pipe.

 

As cheap as catalytic converters are today added to the fact that they now can flow very good and help act as a muffler I don't see a good reason to remove it. If you remove the cat(s) you may notice a gas smell. Some people claim they never noticed anything and others have said it's very noticeable. Myself, I definitely have a gas smell and now being older I am considering putting a high flow cat back on.

 

I 2nd Tibo. With my cat removed and straight pipe welded in I get much more exhaust smell around and even in the car. So much so that I am planning to put a new cat back on in the coming weeks.

 

The smell of exhaust is worse but only at start up. Once warm no difference at all. I really like the way the pipe made the car sound more than anything. Also this is a slip fit on one end and collector style on the other so it can easily be removed.

I have an 03 Silverado for my DD with the stock exhaust still intact and that thing smells worse than the Z until it warms up!

 

The exhaust smells different.. I don’t think it’s a stronger smell.. The stock exhaust is a little sweeter (not anti freeze sweet) and without a cat I feel there’s a burnt popcorn smell.. My 87 and my buddies 88 both had punched cats and had the same smell.. It did sound better without the cat.. not sure what the new high flow cats sound like..

 

Those of us old enough to remember a lot of pre-emissions cars on the road (emissions controls were just becoming a thing when I was born) recognize the smell right away. There is a distinctly different smell to it, and I've had a few people comment "you smell like car," after I drive something without converters on it.

My $.02- if it has a "modern" monolith (honeycomb) style cat (as opposed to one of the big flat "bed" style cats) just leave it till you're making a lot of HP and/or need to do something with the exhaust. At more normal HP levels a Flowmaster muffler will pose a bigger flow restriction than a good cat. For a long time, my "racecar" had headers, dual high flow cats and straight pipes back from there. I was not loosing any power to running the same setup without cats and a high flow muffler, it sounded good and ran clean/passed emissions. I would run the same setup on a sub 400-500hp car in a second from a performance and sound standpoint.

Secondly, if you drive the car a lot, be aware that even though you don't need to have them to pass local laws (same here if it's registered as historic), removing it is still a violation of federal law that prescribes fairly serious penalties for removing it ($2500 for being the one removing it which makes it hard to find a shop to do the work unless you know someone, up to $10,000 for having it removed) and there are remote, roadside detectors that can detect gross emitters as you drive by. I know in MD they've at times set up and impounded cars going to the beach, and I've heard of other similar setups on the east coast. I've considered adding something that looks like a cat to my current "race car" (even though cats that size don't exist) just because it does see a lot of street driving, even though it technically doesn't have to have one.

 

I’m curious how they would be able to detect emitters because my 87 IROC could actually pass emissions with the hollow cat that it had. Barely, but it would pass with the probe up the tailpipe. I didn’t have the smog pump connected either. Bought the car that way and just never had a belt on it. Previous owner put on a power pulley and disconnected the smog pump.

I didn’t have headers on that car and just had the regular Flowmaster that everyone had (I think the 80 series).. so it sounded much better without the cat compared to cars that had the cat intact. It’s an easy way to get more throaty sound, but maybe not technically the “best”

It’s so nice not to worry about emissions anymore!

 

I have a much different experience. I have no cats and I have a distinct gas smell. Its not a sweet smell or any pleasant smell, its a gas smell. I've got it tuned with a wide band and my idle is 14.7:1 AFR and it still has a gas smell. I don't mind it but lately my hospital has cracked down on employees that have a smell about them whether it be unpleasant (cigarette smoke) or pleasant (cologne). I'm not wanting to test them and be sent home because I drove my convertible to work and I smell like an old car or lawn mower. I recently bought a pair of "high flow spun" converters and will be installing them.

 

That stinks.. literally.. I’ve never been around a thirdgen without a cat that had a gas smell.. it sounds like it may be a combination of things but do what works for you for sure.. I’ve gone in the garage in winter to shut the car off after it was running with doors and windows open and people said I smelled like car, but no one or myself ever thought it was a “gas” smell. It was a T-Top car and never had an issue of smelling like exhaust.. I know it’s off the table for purists here, but do your exhaust tips go past the bumper? Even a smidge past the bumper will get the exhaust out behind you.. The way the pipes point down from the factory isn’t the best for that..

 

Dumps straight down before the rear axle.

 

That might be your issue with the gas smell.. the gasses are hitting the ground and back up into the car.. especially when stopped and idling.. I’d try getting the exhaust out behind you.. Might be cheaper than getting two high flow cats installed too and might not solve the problem.. a couple pipes and some welding for $100 or so.. go to a custom exhaust shop and tell them what the problem is and what you want.. they can probably make it look more stock too..

 

To an extent it would help, but again, with as cheap as converters are now along with me being able to weld my own custom exhaust it's not worth me arguing against.

 

That’s awesome you can do that yourself! Always wished I had a lift and the ability to bend cut and weld pipes..

 

Don't need a bender at all, YouTube Pie cut exhaust or pay a little extra for the pre bent kits out there.

 

While I don't advocate removing catalytic converters, I seriously doubt that Feds are going around fining people for removing cats from their old cars. In fact if you've been following the News lately, the Feds are pretty lawless themselves...

 

I think you are right on this, not stronger, just different. I also switched to Non Ethonol gas which made it smell different even before I removed the cat.