I'm getting ready to do my exhaust this weekend....im pondering putting on flanges on my cats, so i can swap em out when i hit the strip...or just when i dont need to pass emissions :)

what are your guys thoughts on this....would a stock 305...posibly with intake/carb/cam see any major benefits out of this? would it be worth the trouble(yes trouble) to weld on the flanges to the cat and pipe....the TROUBLE part is that the cat is a different OD then the pipe i'd be connecting it to....so basically summit has several different ideas of what 2 1/4" pipe is...grrr :evil: :evil: :evil: boy was i pissed when i pulled the calipers out to find that....any suggestions PLEASE HELP!!!

Be kind to the enviroment and weld the cats in place. It's not worth all the trouble to do what you're proposing. You'll see no improvement in performance without cats on a stock 305.

:mrgreen:

hehe, yeah i suppose, i figured there wouldnt be much of an improvement....oh well, i'll have plenty of time to kill the environment when i swap my engine down the road :)

well, ive found the thing to do is take off the converter and hollow it out with a crow bar, or whatever is handy, then put the hollow cat in place an weld. then it looks like you are not breaking any laws, at all....

You could always get a high flow cat, i think summit and jegs sells them.

well, ive found the thing to do is take off the converter and hollow it out...
http://elcaminocentral.com/users/elcamino/eusa_naughty.gif That should not be encouraged in this forum.

The federal "Clean Air Act" prohibits the removal or rendering inoperable of a vehicle’s catalytic converter or any other emission control component. Generally, a vehicle’s emission control system, including the catalytic converter and any other design element of the system, may not be changed from the EPA-certified engine/chassis configuration without violating tampering prohibitions. All such emission control elements may not be removed and replaced by any service or repair facility, or by any private individual, unless the replacement part is designed to perform the same emission control function as the original part.

Should an individual and/or a service and repair facility be found in violation of federal clean air regulations by illegally tampering with vehicle emission control systems, the penalties are up to $2,500 per violation for individuals and dealerships can be penalized up to $25,000 per violation.

http://www.epa.gov/otaq/cert/factshts/catcvrts.pdf

:mrgreen:

The Judge has spoken. :P Ouch! 8O

i work in a chevy dealership and am aware, of the tree huggin hippe laws of the epa. i was just telling him an option i know of. if you do not agree with it and that is fine. he probobly doesnt either, but he asked a question and i gave him an answer, but dont think that im ignorant of the law. i know the law, i know the fines. and my converter is intact an on my car. one of the mechanics in my shop told me about this option and i took it into consideration.

also i just looked in the state inspection book, and converters are only required on cars after 1984. i have an 82. i have a converter but now that i know i dont have to have it im taking it off.

My impression after talking to several national chain muffler shops is that the requirement for a cat is a Federal law, not a state law. When Oklahoma eliminated inspection stations and the associated emission checks I eliminated the computer during my engine upgrade and wanted to delete the cat. I ended up installing a free flow cat.

I only have one comment...The Braves are down 1 in the ninth, doh!

Today's cat's are much better free flowing than originally designed for your vechicle...put them on and be done with it. If you're that concerned...have cutouts installed for race days...just a thought.

hmm... i work at a dealership and i looked at the inspection "rule book" and it said that they are only required on 84 and up. so i dont know... mine doesnt work any way, thats why i want to take it off. not sure. i just dont know what to think any more.... o just finished putting on air shocks. so im happy...and tired.

Having a cat. on any car that originally came with one is a federal law. If you are not in a emmisions county than they ussually do not worry about it. If I am not mistaken Caminos after 74 have cats. The guy that I take my cars to said that my 78 will be exempt after next year. Union County NC, but I will still keep my aftermarket cat.

Be kind to the enviornment get cats. Don't get the junky stock GM cats but some highflow cats. Only difference it will make is less polution. ETs should not change at all.

how often does the cut off date move up for exemption on vehicles? next year will it be 79?

My understanding on Fed vs State is that the presence of the cat on the new vehicle and the emissions warrany are Fed requirements, but the annual safety / emissions inspections are a State matter.

This is why (at a minimum) Fed emissions are on all new vehicles, but state-to-state you range from annual to semiannual to no inspections. States where the EPA has brought the hammer down need to establish an emissions program, but that's a special case, and even there the details of implementation are up to the state so long as they meet the requirements.

So, it depends on your state's laws. In NC, the most recent incarnation of the law uses age as the exemption from tailpipe sniffing, so it slides up every year. HOWEVER, a new tweak is a sentence that appears to indicate that there is supposed to be a physical presence inspection for all of the OEM emissions equipment, including cat, air injection, EGR, etc. for ALL vehicles, regardless of year of manufacture.

The emmisions guy I use said that NC drops a year every other year. Last year it was 77 so next year its 78. He told me he would just inspect safety eq. like lights & horn. etc. I will keep the cat but the vapor canister & its hoses has got to go.

If your so worried about the environment, its time to get a car with a 4 banger and put that gas guzzling V8 to rest.....




...or give it to me :P

If you really want to get as close as possible to a free flowing system get a catalytic converter from Random Technology. They are Number one when it comes to free flowing cats...a little pricey but if you are worried about all that stuff go with them..

I don't like tree huggin hippies :mad: :mad: :mad:

I don't like tree huggin hippies :mad: :mad: :mad:
hehehe... me either.

Hi,
Check out the following link. I came across it in the last week or two. If I can find headers for my 229 v6, I'll work with that. (I'm not looking for a really powerful car - just something a little more fun. Looking into an Edelbrock cam kit/intake/carb as well.) They're on the east coast no less!

Lee Campbell

http://www.pypesexhaust.com/contact.html

I don't like having cats on my cars at all, in fact it really pisses me off. I think they should be outlawed. I don't think they really do anything at all to help the environment, and anyone who says otherwise is a moron. When I see cats on my cars, I go get the hose and spray them until they run away.

:P :P :P :P

Read the discussion and found it helpful. I am about to redo my exhaust as the rust rodent has eaten too much. I will plan to keep replace the cat with a higher flow model. You have already answered my wondering about performance, but here's another one I'd love to get feedback on. Any benefit to installing a split system behind the cat? I like the look of two pipes at the rear, even if it is a fakeout. Could such a system actually help breathing and perhaps performance even a hair? (Would hate to expect some good for the extra bucks that doesn't come to pass!) :cool:

also i just looked in the state inspection book, and converters are only required on cars after 1984. i have an 82. i have a converter but now that i know i dont have to have it im taking it off. I thought 1975 was the year of the cat.

I can't seem to find my cats, computer or PCV anywhere. Where could they be?

PS If you find them, keep them! :P

PPS Don't hurt me 87ElCamino :cry:

PPPS I'm not suggesting anything :sly:

PPPPS I'm running out of Ps :P

Sometimes 2¼" is ID and somtimes it's OD. This lets one slip into the other. :-P


I have flanges on mine. Disconnecting it doesn't help ET because the high flow cat isn't the bottleneck. I sometimes swap between the high flow cat and a hollow cat when I run leaded race gas.

Using a split exhaust system behind a catalytic converter will not enhance performance because the catalytic converter would be the restriction. A better choice for performance would be a true dual exhaust system with 2 high flow catalytic converts and it would still be legal most anywhere in the country. I am glad that here in Hawaii we have absolutely no emission control regulation compliance testing whatsoever. Because of the almost constant tradewinds smog is never a problem except for the rare occurance of "vog". When we have severe volcanic activity and no tradewinds the volcanic emissions hang over the Islands causing "vog". The treehuggers haven't figured out how to put a cat converter on the volcanos ..... yet.

In Tennessee, model years 1975 and later must be inspected, in those counties affected. Not all counties are required to inspect for pollution. I am not aware that any model years drop off as time marches on. Is it a state issue? If federally controlled, I do not think any model years would be allowed to drop off the inspection schedule. However, may be wrong.

Appreciate your input Mrapii. A true dual system w/ high flow cats is what I think I'll do. Regarding performance, have to wait until the 305 wears out before I can switch the numbers to a 350. Problem is, I am the second owner of the elky, the first being a mechanic. We BOTH have babied the car, and it may be awhile. :-( But, something to look forward I guess!

I had a 2 1/2 performance cat ,it then split into 2 1/4 pipes to turbos out the back. The biggest restruction is the y pipe connecting the manufolds to the cat. My 78 become smog exempt this year so I installed headers & true duals to the turbo mufflers. I felt a big difference in performance & increased gas mileage. The engine sounds so much healthier too. It's just what my performance 350 needed. :)

Three words, F*** the treehuggers

This is obvious as I am redoing true duals with 40 series flowmasters. No cats here. State law requires them '83 and newer. Now back to the treehuggers. in the immortal words of Holy Grail, I fart in your general direction, I wave my private parts at your aunties! Your mother was a hamster and your father smelt of eldaberries! If you haven't seen Monty Pythons Holy Grail, how can you be part of the counterculture revolution we all joined by owning El Caminos.

For the whacked out environmentalist who thinks trees are more valuable than people I agree with you 1982 SS. However I don't mind clean air and clean water. I am old enough to remember Los Angeles during the '60s and i can tell you the smog was not pleasant. I have been in the auto industry for over 40 years and I reluctantly admit that if not forced by legislation I don't think the auto industry would have been so quick to clean up the gasoline internal combustion engine. Modern technology has proven that we can have both high performance and clean air.

The words "performance" and "catalytic converter" don't fit well together unless maybe you add in the word "Borla," then they fit a little bit better together.

Modern technology has proven that we can have both high performance and clean air.

Amen to that!

Like I said, when I unhook my converter (and the rest of the exhaust), I see no gain in ET.

Earlier design pellet bed converters where restrcitve. MODERN monolithic converter are not. They also don't need the extra AIR to function properly, so I removed the smog pump. Passed emissions testing without a problem.