I'm in Arkansas - 1982 Corvette switched over to carbed engone, no smog equipment. As basic as you can get. I'm lucky to be in one the states that doesn't have strict smog laws or have to go through an inspection to get tags.

But can someone point me to a site or give me some info about the laws on these?

I've heard several different things about catylic convertors on various forums on the internet.

1. If the vehicle is more than 25 years old that you don't have to use them

2. If it didn't have one on it when you bought it you don't have to reinstall it.

3. If it originally came with one you HAVE to keep one on for the life of the vehicle.

Any ideas or input? I'm redoing my exhaust and would like to make it pre-1974 true dual exhaust style

But want to find out current laws before I do so

Thanks!

 

From my understanding if your vehicle came with a Cat you have to keep the Cat. This is one of the reasons I liked the 74 because it was the last year of the "true" dual exhaust. The Feds are really strict about these even to the point that a shop that alters the original exhaust will be fined (a buddy of mine in NY found out with a $25,000 fine for altering a 89 Vette). My advice is too look for some preformace parts while keeping the exhaust original; I.E mufflers, headers, engine mods etc.

 

3. If it originally came with one you HAVE to keep one on for the life of the vehicle(this is correct)...

I got away with duals/cats in Calif....till I had to finally replace them..no shop would touch the job..only one Cat allowed...in your case,I would install the duals myself and not worry about it..afterall,you have no inspection,right ?

 

Sorry. Cats are covered under federal law. They must remain in the same configuration that the car left the factory with.

Almost no muffler shops will touch anything but the original setup. If you want to eliminate the cat or add a second one, you better find yourself someone that can weld or learn how to do it yourself.

Getting it past inspection is another matter altogether. If you just have visual inspection, you will have to find someone that either doesn't know what was supposed to be there or just doesn't care.

 

Technically, you would be breaking federal law. However, if nobody in your state cares -- you don't have inspections of any sort -- who's gonna catch you? And you may find muffler shops less worried (or not worried at all) about this sort of thing.

If the shops won't touch your car, there are "off-road" true dual kits for your car from Mid-America Corvette. You cannot install an actual pre-74 system due to the different transmission crossmember used in later C3's.

Remember, however, that if you still have Crossfire injection you'll need to make provisions for an O2 sensor.

 

Thank my lucky stars that I've got a '74 and don't have to deal with that here in California.

If your car has a cat, you MUST keep the cat. No ifs, ands, or buts. Doesn't matter which state you're in...And since it's an '82, you should have a cat.

Now, seeing as how you're in Arkansas, you might be able to get away with one of the "high flow racing catalytic converters" that I see advertised in many hot rod/tuner mags; they're not legal for use or sale here in California because of screwball regulations. (It's even worse on my Saturn; I have a pre-cat built into my exhaust manifold; when that goes, you have to replace the entire exhaust manifold because the pre-cat cannot be cut out and a new one welded in)

 

Gonna clarify this. If you car has a cat, according to federal law you MUST keep the cat.

It's up to you whether or not you want to break the law...

 

How hard would it be to put headers and a true dual exhaust on my 79? I don't have any emissions laws or anything where I live in washington and if I can't find someone to do it, I'll figure out how to do it myself.

 

i did the same thing on an other make of car. came wirh a single exhaust with one huge cat lengthwise. muffler burnt out. found a supplier for a off road down h-pipe bolted on changed the xmission mount and the rest is history. true duals. car runs better. cat was junk after 130k anyway.

 

Thanks guys,

I just ordered a stock 76-81 cat converter for my application off ebay for $98 shipped.

It wasn't really a matter of trying to gain HP, I was just being a cheap a$$ and didn't want to spend $140-160 + shipping for a replacment converter since I started redoing my exhaust. The $98 was a little easier for me to swallow and I won't be breaking any laws.

I'll have the 80-81 style exhaust under my car instead of the 82 style. I ended up getting a good deal on a replacement front "y" pipe that was designed for 1980 with ram head manifolds. (since thats whats on the car now w/o smog equipment or computer)

Now I just need the rear "y" pipe and I was looking at some 40 series flowmasters to round everything out.

 

someone is generalizing about the law.

just because there is no "inspection"... doesn't mean it's legal to remove the cats. Like someone said earlier, if the car originally came with them ... then they still must be installed and working.
All that "no inspection" means is it'lll be much harder for the feds to catch you.

It's federal law - about not removing smog equipment. States can't circumvent that.

you can get the car re-titled to say it's a "custom" or a "kit car"... and maybe can escape the smog engine laws.

 

My car, 76, is licensed as an antique which means it no longer has to have annual safety inspections which is where the cat thing comes up. However, you sign something saying your car complies with all the laws. It's assumed it will be a light duty, few road miles car as an antique and will not be driven to work, will only be driven for occasional pleasure use and to shows. If i did the work myself i'd put true duals on but since I'm having a shop do it we're going with two duals straight back through two high flow cats and mufflers behind. Will pass moral imperative for cats and the shop doing it won't take a chance on violating fed. law. Also takes cross section of air flow from 9+ inches with one 3" pipe into cat to two 2.5" or almost 15.7" of cross sectional area which will be significant.

If I could guarantee only off road use then true duals. People here do it all the time and take their chances but they do the work themselves as shops have too much to risk doing it for you.

Lance

 

I see loads of later model C3s on this site with side pipes (obviously no cat) and wondered how they get away with that. It is one thing to have true duals hidden under the car and another to blatantly advertise that you do not have a stock exhaust system.

Is there anyone out there reading this that had done this mod and had to take them off? I would love to have them on my 79, but I know I will never get a shop to do it and even if I did install them myself or with the help of a friend, I don't want to go to that expense and have to remove them and maybe even be fined.

My car is definitely not a daily driver and the place that does my annual inspection doesn't check anything on my car. They just put a new sticker on it. I am not that worried about getting caught at inspection, but have wondered about the local police stopping me because of one thing or another and citing me for having side pipes and non-stock exhausts.

My exhaust is still stock, but I do have a test pipe! Have not installed it - yet. At least that is something that can be taken off prior to inspections and not obvious while being driven. I sure wish I had kept my 74!

 

The law is Federal. The enforcement is up to the states. Some enforce it, some don't, some put conditions on the enforcement. All depends upon where you live. You are lucky to be in Hog country.

tom...

 

For what you guys without inspections, and no welding ability...cut the damn thing outta there, cut a pipe to length, no flanges no nothing....take 4 hose clamps and some galvanized steel like from Lowes Despot, and wrap the joints pretty tight with 2-3 layers.....clamp each end of each pipe....you can run for years like that....use stainless hose clamps....but you have to cut on a fairly straight section of pipes so the splices will seal decently.....

BTDT....

 

I've heard stories about guys taking the original cat off the car and cleaning/hollowing it out with a piece of rebar and then reinstalling the shell back on the car. Not that I'd recommend this... Pass your visual inspection with no issues yet have the improved performance.


As for running no cats on OEM cat cars, it's all dependant on your local law enforcement.
My car has Hookers, but I register it as a "show car" and the BMV gives me an "exemption" for emmission checks. In my state, the BMV also has an "exemption" for registered "antique vehicles" which is how I plan to register it this coming year. I'll even get a special "antique" license plate.

 

You did this to your Corvette?

 

Duct tape!

 

I live in Pa and I also am a licensed Pa auto inspector. Heres how the law in Pa is written. Any car that is driven in a 12 month period less then 5000 miles and has been owned by the same owner during that time period is considered exempt from the state emissions test. The 12 month period is from your last inspection to your current inspection. Now if your car has 5000 miles or more during that time period or you have not owned that car for at least one year then it must comply with the factory / federal standards. However, 1975 thru 1995 goes through a visual test only meaning that parts are verified to be in place and "appear" to be functioning. This means that a converter or air pump could be gutted but as long as it is on the car and appears visually correct I should pass this car for emissions. I am not required to actually test the parts but just visually verify there appearance to be a functional part. Its a fine line but thats PA! All states vary in their laws. This is just Pa's.
Rodney

 

Here in Va. you can get as I did an antique plate at 25 years. It means you pay once, do not have to do annual safety inspections but you sign a form saying you meet all applicable state and federal rules which included the EPA rules....

It also means the car can never be used as a daily driver and is meant only for occasional pleasure use and to shows specifically. That is about what mine does so will be fine and I'm retired.

No one here really inspects and many do drop the Cat entirely but do the work themself as shops if they get caught doing it can still get a big Federal fine and it isn't worth any risk to them. Just dropping in an engine like a crate stroker or a big block or more modern engine alone would technically be a violation as none were offered in 1976 and many of the larger engines through high flow cats or bullets or none at all generate a lot more exhaust but it's commonly done. Fact is, they don't check here once you're done with regular plates and safety inspections.

By exception they can however. If you get into difficulties and anyone looks they can. Too many other important things for law enforcement to do and the state implements federal epa rules anyway but that's the situation. I'm happy to have the choice to have new high flow cat's available. Will have two 4" "Bullets", one on each straight exhaust back to new mufflers. Will be interesting to see how it sounds and feels to have a non leaky, working exhaust system with approx. 200% more cross section flow area for a change on the '76. Should get it back tomorrow.

lance