Is 1978 vette 4speed manual has true dual or its also has Y pipes just like the automatic transmision????

 

All 78s had Y-pipes fore and aft of the catalytic converter.

 

True duals ended in 1974.





For everything.

 

Sucks....... im guess im stuck with Y pipes. its so strick here in california. They wont let you modify your exhaust system.

 

I have a 79, L82 and I installed true duals from Corvette Central. Since you live in CA could you not install duals with high flow cat and meet the state requirements?

 

requirements said that you cant change it. It will not pass the visual if they look under when i smog it (if the look under ha ha) but im guessin wit will pass the emmsion cause i will but 2 cats if i do. so im still undecided if im getting true dual or stickin to Y pipes with 2.5 inch pipes. But Im sure its gonna sound better if i get true duals thats why im undecided.

 

Technically that isnt legal anywhere in the entire United States, its not just California. This is a federal law that deals with that.. However because California has emissions inspections its easily caught here.

States which have no inspections, or minimal inspections it is easy to do things such as that and succeed.

Inspectors here are taught to look under the cars, and they generally know what to look for. Of course some dont look, and there might even be a few who dont care (those however are risking fines or even their license to inspect if the State ever catches them passing a car that should otherwise fail)

 

Can;t you register it as a collecter, or whatever, and the put less than a certain amount of miles on it, and be fine?

 

I know it's frustrating, but seems like having cats on both exhaust should be acceptable. I retired from the CHP in California and I used to have difficulty getting my vehicles registered when I did any modifications. I used to live in Encinistas in San Diego County

 

Yeah, one wonders why "it passes" isnt good enough. I doubt many would find much fault with JUST a sniffer test. Logically if it passes that (and ok the Evap portion too if you want to be pedantic) how you get there really shouldnt matter... but alas

 

I posed this very question today to several inspection stations North of Dallas, TX. I am in the process of deciding on installing true duals on a ZZ4 being installed in my '79. All of the shops are in the county where the car will be registered, and this county is under stricter emissions than a majority of the counties in Texas.

Every one of the inspectors I spoke to said the car would pass no problems with true duals. There will only be a visual inspection to see if cats are present on each pipe, and not leaking. There will be no testing to see if the cats are functional. There would be no emissions testing since the car is older than 24 years.

God bless Texas.

 

. but i don't think that cats are required on one that old.

 

Well, there was some confusion on that from the techs as well. A few said if the car has a catalyst sticker in the engine bay, they would check for cats being present. The others said "Why we would we check for that?"

I guess it pays to know your inspection station.

 

Even though cats were factory installed starting in 1975 Texas doesn't require them until 1984.

 

Here is what is causing the confusion.

This is straight from the inspection requirements published by the Texas Department of Public Safety"

"The exhaust emission system was installed by manufacturers of motor vehicles beginning with model year 1968. The inspection of the exhaust emission system will apply only to those vehicles that are equipped with such a system. The following exhaust emission systems will be inspected if installed as original equipment by the manufacturer: thermostatic air cleaner, exhaust gas recirculation system, positive crankcase ventilation system, air injection system, evaporative emission system, and/or catalytic converter.

If installed as original equipment by the manufacturer, the catalytic converter will be considered a part of the exhaust emission system on all 1984 and later model vehicles. It will be inspected as a part of the exhaust system on prior to 1984 model vehicles."

The way I read the last paragraph, you need cats if they were factory equipment. Am I missing something? If I can save a few hundred $$$ by skipping cats, fine with me.

For more confusion here are links to the inspection requirements.

Texas Exhaust Emission Sytem Inspection/Rejection Criteria:http://www.txdps.state.tx.us/vi/insp...ejectsubmit=Go

Texas Exhaust Sytem Inspection/Rejection Criteria:http://www.txdps.state.tx.us/vi/insp...ejectsubmit=Go

Enjoy the headache after reading this information.

 

I was a state inspector back in the late 80's & that wording hasnt changed since then.
While I dont know If they are told different now, we were taught to only look for converters on 84 & newer cars.

 

Nobody's taken it to court, that's why.

 

In CA you can register your car at a high-altitude zip code that is exempt. Who do you know with a cabin in the mountains? Check the DMV website for exempt zip codes near you.

Here in San Diego area, both Alpine and Julian are exempt zip codes. The ONLY downside is that you need to be mindful and re-register yourself every year by bringing your registration in & paying for it before it expires.

 

Anyone have two exhaust systems, one to get the car inspected, take it off and put on a more performance enhancing system?
I still remember getting rejected in 1973 for a state inspection because my 68's taillight lens had hairline cracks. Just went to another inspection station and received the inspection. The taillight lens are still on my 68 light up great.

 

If installed as original equipment by the manufacturer, the catalytic converter will be considered a part of the exhaust emission system on all 1984 and later model vehicles. It will be inspected as a part of the exhaust system on prior to 1984 model vehicles."

84 and newer falls under federal and state emission laws. 83 and older falls under state safety laws. Big difference.
Being inspected as part of the exhaust system simply means no leaks or improper repairs. On a non-compuiter car it is inspected visually only. To put it in even easier terms if the cat is on the car is must be mounted properly and not leak.