VolVette

I have a '75 with a ZZZ crate engine, original manifolds going to single pipe to catalytic converter, after converter splits into two pipes that go to my flowmasters. I recently purchased Dynomax CeramaCoat headers with intention of installing them and having a shop go to straight back duels from each header. I called a friend's muffler shop and told them what I wanted and they said that they wouldn't remove my Catylitic Converter!! :mad So, now I have my Dynomax Cermacoat Headers ready to be put on with true duel exhaust.... Do you have any ideas how I can get this done? I don't have the equipment to weld... Do you know the legality of removing a catylitic converter?

I appreciate all of your help.

Stephen :confused:

terryrudy

Haha, I had same dilemma. I swapped out my headers myself and drove the Vette with open headers (ooh boy did that sound awesome!) to a local Midas and had them do the rest up for me. I provided my own mufflers and they put the true duals in for about $350. Eventually I want to get dual cats but not until I NEED to. :)

If they would have asked me what it came with (I doubt they would even care) I'd just tell them it didn't come with cats. But maybe I just got lucky...
-terry

john's '81 mouse

Believe it's true that for most, if not all states, it's illegal for shops/garages to remove the Cat. Convertor, however, in many states it's still OK for shop to install new exhaust system without a Cat Convertor, just as Terryrudy explained with his personal experience.

You probably need to get suggestions from someone in your state (VA?), and they could give you the best suggestions, or make a contact with your local corvette club, as they might be able to help as well.

82dukman

Take everything off yourself and loosely clamp it together to get you to the muffler shop. If you already have the pipes that is

mrvette

I'ts not state, It's freaking FEDERAL,. against law for any commercial operation to remove catastrophic converters without replacing with same near identical routing system....
now having said that...even the smog ***** have not gotten to the indivudual owner...YET!!!....so YOU can do anyting to your car you want...and if that cat-butt-trophic converter is missing, I THINK the fine point is the exhause shop is not forced to replace it.....

but I have never gotten an exhaust shop to remove and not replace a cat...

it's major fines and assorted bull......

so as allways, to get it dun rite, you gotta DIY, .... :D :eek: :mad :rolleyes: :cool: :cheers:

79MakoL82

Unfortunately, it is a FEDERAL law that they cannot install anything that the car did not come with, or could be optioned with, in the year it was made. As Corvette's did not come with true duals from 1975-1982, a shop cannot "legally" install them. That is why the dual exhausts that are sold for 1979 and on are advertised as "For off road use only". HOWEVER, there's ALWAYS some shop that is willing to do it for the money. Your larger chains usually won't. Find some small shop and tell them you'll make a deal, "You don't know where the exhaust went, and I don't know who installed them". If ya know what I mean. ;)


P.S. It doesn't even matter about the cat. Even if you installed dual exhaust with TWO cats, it's still illegal. They cannot alter the exhaust configuration from anything that the car would have originally come with. Meaning, legally, you have to have aq 2-1-2 exhaust.


[Modified by 79MakoL82, 3:44 PM 1/9/2002]

ZD75blue

wait one second... lets show them that they could be ordered with true duals... ever seen the high perf. off road system on an order sheet?

wonder if we found a loop hole? pray :D

jerryp58

Trust me, I didn't have a 2-1-2 system put on my car because I liked it :rolleyes:

I feel your pain.

I'm not sure that there's any way around it, except to find yourself a shop that will put a dual system on (you may still have to take the CC off yourself). Also, keep in mind, you may be able to find a shop that will put the system on, but that same shop may not pass the car for inspection. If you decide to try duals, make sure that you can find a place that will inspect it. Of course, that opens up a can of worms too, because if you ask someone who doesn't really know you if they will pass your car with duals (even dual cats), a LOUD alarm will probably go off in their heads that they may be in trouble if they give you the WRONG answer.

Someday, I think I'll try duals, probably with dual cats. But for now, with the car as my daily driver, I think I'll keep it "legal". Of course, I may wait until this system has a few years on it and pull it off before it rusts together or rots, have a new dual system put on, and keep the old 2-1-2 in case I'm told my car fails inspection. Then I'll just swap the two out for inspection. A pain, but maybe worth it.

Good Luck.

ZD, you said: "wait one second... lets show them that they could be ordered with true duals... ever seen the high perf. off road system on an order sheet?" What is this about? If it is an "off road system" that sounds like it's already illegal on the street. :confused:

Ganey

What emision standards before 80 :eek: http://forums.corvetteforum.com/zerothread?id=213813

The 76 GM manual shows a chart w/ duals for the L-82. :eek: Jack Sweet brought this up.

The 77 GM manual shows a pic. of duals & has dual replacement instructions.
I brought this up.

We have posted about this before.

:cheers:

Captain Morgan

I'm not sure what the inspection laws are in your state, but it may still be possible for you to have the exhaust you want. You may have to tell them it's a 74 but no matter what, you'll have to remove the exhaust at home. Most big chain places won't install anything without knowing what came off it but you might get a hole-in-the-wall place to install what you want. Just don't tell them it's a 75. Of course, then you have the problem of a visual inspection when you register, if your state does that. However I knew a guy in another state with inspections that had an 81 and installed true dual chambered pipes on his and gets away with it. He said that when asked, he just says that's the way it was when he bought years ago and that's the way he replaced it when it started rusting out. He says that Federal law didn't require cats until 81 and his must have been one of the ones before the law past. It is possible, you just have to know where to go to get it done. And remember, you're vette is a 74 if they ask. Check with local Corvette clubs and you may even find someone who can weld and is willing to do it in a garage. It can't hurt to try.

jerryp58

Ganey, I took those pics you emailed to a muffler shop and asked if he'd do the duals. His take was that the duals were generic GM info. Everything he had on the Corvette said it came with one CC and that was all he could legally put on the car. Actually (I guess since I had removed the entire exhaust), he said he would put a dual CC system on for me, but that he wouldn't pass it for inspection. I could have taken my chances and tried to get it inspected somewhere else. That's when I asked around at a couple of places. They might have been playing it safe because they didn't know me, but they all said, NO WAY; one CC only. I guess I just don't know enough people.

As far as that emissions standard goes, there may be a lawyer out there who could argue it, but I doubt that, just because the early CCs didn't do a good enough job to meet the required emissions of '77 and they had to extend that requirement out to '81, that would allow us to not have the required one CC. Heck, if any of it made sense, then they wouldn't stop me from putting a dual system on that might actually better the requirement.

Jerry

Ron 75 L48

Jerry, do they actually do the sniff test up there in colonial heights? I asked down here in virginia beach and was told by the guy doing my inspection that all he checks for is that there are no leaks in the system. The guy told me that "legally" I couldn't put true duals on my '75 but when I get ready to let him know and he will send me over to a friend of his that does exhaust work and I won't have a problem with getting it inspected.

Ron

jerryp58

Ron, no, the car has never been sniffed and as far as I know, there's no requirement for it here. In my other post, I was speaking of the theoretical situation of "failing inspection with a dual system even if the emissions rating were better". As far as I know, that's the stand of the inspectors & muffler shops here. Gotta have ONE CC! I know there are people around here (and everywhere else) that run dual systems (I've even seen a '77 here with side pipes). I guess I should get to know some of these people so that I would know where to go to have my system done AND passed for inspection.

81vette

Your inspections may be different, but in Texas the inspectors are not required to look for cats on cars older than 84'. Some inspectors may look, but most won't look if they aren't required to. In the past 7 years I've only had one inspector check under the Corvette for the single cat. He told me before he even looked that if I didn't have the old style pancake cat he'd fail me.

Just don't walk into the place and advertise the fact or say anything about your pipes, cats, or emissions, because your inviting him to look and fail you. You should know whether your going to pass based on previous inspections. Did they look under your car for cats then? If not, then your probably ok. If you haven't done an inspection before then take another car down to the station first or go with a friend and see how they operate.

Mark




[Modified by 81vette, 8:20 AM 1/10/2002]

Ganey

My post was about getting it inspected after done. In general if the car looks good, they don't even look under it. Many have reported passing w/o cats in places where the ex. is tested, that EPA link referred to may explain why.

Neo Fender

A 3.5" pipe has the same cross section of two 2.5" pipes. (please everyone, don't try to tell me that only a 5" pipe can be double the cross section of a 2.5" pipe - it doesn't work that way). A lot of late model Camaro and Firebirds use a single 3.5" pipe for aftermarket exhaust systems because the chassis will not accomodate a dual pipe setup. The problem may be finding a converter that will accept a 3.5" pipe. You still may have to reduce it down to 2.5" at the converter if you feel that you need to keep it.

Ganey

Some later models like 86-88 Monte Carlo SS have a large oval in/out cat.. The oval shape does not matter & helps clearance. You still have the bends (not rec.) in the exhaust to cross over.

VolVette

Well... Let's see...

I think I will get my Vette inspected this month and then replace the headers and try to get a friend to do the exhaust swap for me. The question I have is: if fail inspection next year for not having a cat. conv. will they require me to put on or what will the penalty be?

VA does not do a sniffer test and as I watch and talk to the mechanics doing my inspection, they usually just put a rag in the tailpipes and check for leaks. So, I should be able to get away with it.

Stephen

Ron 75 L48

Go for it Stephen. I don't think you have anything to worry about here in the Hampton Roads area.