cats are smelly

[poorboys831]

My '93 has 140k miles and there is an oder that tells me the cats are done.My question is:besides the legallity,what would be the problems in removing them?-Back pressure?-noise? thanks Dennis

 

[Ken]

First off, the wonderful sulphuric smell given off by the catalytic converter probably is not due to the cats being old or worn out. That smell usually comes with an over-rich condition, which sometimes will occur briefly while driving in traffic. I wouldn't worry about the cats until they either start making a racket, indicating that they are breaking up, or if there seems to be excessive restriction in the exhaust. If the latter is the case you would notice a dramatic decrease in performance.

There are free-flowing cats available on the aftermarket, such as Random Technology, but the factory catalytic converters are pretty good to start with.

In answer to your question regarding noise, the cats do quell the exhaust tone almost as much as a muffler.

Hope I helped. Others will chime in shortly.

 

[vader86]

Well since we have no emissions in SC, theres nothing stopping you from takin them off.

Totally removing them would probably free 5-7hp, which is not much, but would also increase your exhaust note some. Not too loud though.

 

[Eagle85C4]

Federal Law supercedes state law. it is a Felony per the Clean Air Act to alter or tamper with a stock exhaust. The cats can be replaced if damaged or if the car has over 50k miles on it. Otherwise you are looking at a hefty fine per day and possible incarceration. And just because you do not have emmissions testing in your local means nothing, any law enforcement officer can turn you in for violating Federal Law as well as D.O.T. officers, as well as any place you take the car to be worked on. Also in the fine print of the Clean Air Act.

http://www.epa.gov/oar/caa/contents.html

 

[vader86]

And i'm very sure youre never EVER going to see a SC state trooper get on his knees and look underneath the car

The change in noise isnt anywhere near what it needs to be for them to get you for a noise violation

 

[poorboys831]

Thanks guys for your advice and thoughts.Believe me the day a cop can get his head under a vette is the day they start hiring pinheads.My mufflers are already off so the car is a LITTLE loud already ,It was that way when I bought it.My main concern is runability and performance.

 

[vader86]

Only problem i could see you having is the same problem guys get with headers, although its fairly rare in practice.

Since the O2 sensors are there to read heat in the exhaust, and youll be removing alot of heat when you do anything to the cats or increase the cross sectional area of the pipes, they may read it running lean and try to up the A/F ratio and cause you to lose gas mileage.

Though, as i said, its rare to have the problem, but it is possible. The fix would then be a heated O2 sensor for each side. Just dont do this until you actually have that problem.

 

[poorboys831]

ah ha-something else to consider-How would heat them if it was needed?I guess I need to get under the car Huh?It's too hot today maybe in the morning-Oh yeah- Vader- have you ever been to one of our car shows in Charleston? The big one we have every year not the monthly ones.We always have a good turn out from the Columbia club.Thanks Dennis