Opinion on Catalytic Converters

SCrazy

SCCoA Member
I am going to install catalytic converters on a pair of flanges so that I can install them for emissions testing then remove and replace with a straight piece of pipe for the 2-years between tests.

What style of converter would be best for passing emissions. No concerns with flow or performance since they will only be on the car 2 days every other year for the emissions test. Really just looking to optimize performance on the emissions test.


Bullet Style Metal Matrix?
Standard OEM style?
9" long body, 12" long body?
 
I would get the largest you can. Im unsure how a low flow style will affect tune and make the car runa bit off . No real experience here however
 
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As far as emissions OEM is the best. Got this form a guy that was in the salvage business, OEM converters are worth money and aftermarket are basically worthless.

There may be better but OEM have to meet EPA standard AND ~100k mile warranties.
 
As far as emissions OEM is the best. Got this form a guy that was in the salvage business, OEM converters are worth money and aftermarket are basically worthless.

There may be better but OEM have to meet EPA standard AND ~100k mile warranties.

That makes sense.
 
What's the Buzz?

You have an after market exhaust system? Then bullet style. They get the job done and you'll never mate the OEM to it. Especially if you have headers.
OEM exhaust then try to find OEM in the junkyard or from somebody in the parts forum. If you have OeM exhaust you likely still have the converters. So use them.
 
Brian, before you go to the trouble, I'd ask some locals if that idea will fly in your area. I know around here, if the cats are obviously easy to unbolt/remove with flanges on either side of them, you'll have trouble passing the visual part of the inspection.
 
Or just befriend a mechanic, pay him with cases of beer, and have the car "slip" through the system ;):rolleyes::cool:
 
Brian, before you go to the trouble, I'd ask some locals if that idea will fly in your area. I know around here, if the cats are obviously easy to unbolt/remove with flanges on either side of them, you'll have trouble passing the visual part of the inspection.

Hadnt thought of that!!
 
Brian, if you want the best aftermarket ones get the CARB cert. ones. If they ask about the clamps just tell them you go thru them frequently. Doubt they would even ask.
 
If you are going to the trouble of buying and installing the cats, why not simply leave them installed? With a good quality high-flow cat that is properly sized, it won't impede flow and so it won't hurt the performance at all. It just seems like a lot of work and the risk of being fined for not having them, all for no gain.
 
If you are going to the trouble of buying and installing the cats, why not simply leave them installed? With a good quality high-flow cat that is properly sized, it won't impede flow and so it won't hurt the performance at all. It just seems like a lot of work and the risk of being fined for not having them, all for no gain.

Mainly because other that for an emissions test I'll be running straight Q16 100% of the time and that stuff chews up cats.
 
I too doubt the clamp will be an issue but is so then have a set of down tubes set up with converters welded on one end and clamps on the other. That way you only have two clamps and not four.

When I lived in Atlanta the SC only got a visual once the 5.0 never did nor did the 96 Cougar, and all that was done was see if cats were there and nothing more.
 
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I can't wait for my car to turn 25 and I won't have to worry about emissions tests. There should be a type of plate hobbyists can get to get around this process. There aren't enough of us to hurt the environment and we don't drive our cars enough anyway. I know PA has classic car registration for 15+ year old cars and they get a pass on the smog test. Here in NH I need to be 25 years old for antique plates.
 
Here in NY I dont need to worry about emissions or anything, and my car is a 94, so 19 years old. Its a very nice thing
 
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