Emissions Colorado 1976 911 Question

[SANDOVAL]

I found out that I have to get an emissions test on a 1976 911 I am bringing from out of state. This is my first vintage car in 20 years so I don't even know if they had Cats in 1976? This is not a stock car so I just want to know what I need to be prepared for. Can anyone tell me what they will be looking for or is just a sniff test and there is nothing to check visually?

Thanks!

[Jcslocum]

The '76 cars had "thermal reactors" from what I have researched, there are catylitic converters but a more primitive system to try to burn excess hydrocarbons in the exhaust. There may have been an air pump too on the engine. The cooling fan had like 5 blades to actually run the engine hotter to help this burning of excess fuel. Google some pictures and you will see the fan for sure.

Good luck and all you can do is hope it passes I guess.

[75 911s]

Colorado has a "Collectors Item" clause as follows:

Vehicles at least 32 years old are eligible for "collector's item" registration. However, in order to register as a "collector's item," these vehicles will require an initial emissions inspection and then must be inspected every five years thereafter at the time of registration renewal. These vehicle have a mileage restriction limiting driving to no more than 4,500 miles per year. If the vehicle is being registered in a county that does not require an emissions inspection, only the mileage restriction applies.

Looks like they also have this:

Kit cars, all-electric vehicles, motorcycles, horseless carriage and vehicles registered as street rods are exempt from emissions testing requirements.

Could you register as a street rod?

What is not stock about the engine and exhaust?

[Walt Fricke]

You should be able to find out from the state emissions people what the emissions specs are for this model 911. Then have a shop tune the motor so it meets those specs. You can generally meet them by leaning the fuel mixture. Then take the car to one of the regular testing stations and see if they do more than test the emissions (typically the CO). They may not even look, and the individual techs may have no idea as to what emissions specific equipment was on these cars in 1976.

I went to a special state headquarters inspection place to get an exception to the equipment requirement for my gray market car which didn't have the heads drilled for the air injection system. They gave me a piece of paper I carefully retained, but thereafter no station looked or noticed that anything was missing, so I stopped offering the paper ahead of time. You may luck out also.
Otherwise, move out of Denver way over on the west slope, or way out east.

[SANDOVAL]

Thanks for the info. It is a 76 backdate hotrod with a 91 3.6L running headers and M&K GT3 Exhaust. I can an plan to register collector plates however I do have to go through emissions testing before they are issued. Once I have them it is no longer an issue. I will cross my fingers, hope for a lenient tech and head in on Monday.

[porschenut]

Originally Posted by SANDOVAL

Can anyone tell me what they will be looking for or is just a sniff test and there is nothing to check visually?

The computer will tell them what emissions equipment was fitted to the '76 911, and they will do a visual verification that the equipment is present on your car. If it came with a cat, they'll require that a cat be there. If an O2 sensor is supposed to be there (probably not on a '76), they will verify that as well.

[darrin]

looks like 1981 and older cars are only required to pass a two speed idle test and that this test can be performed at approved independent facilities -- see Air Care Colorado :: 1981 & Older Limits Might make sense to try an independent facility first -- see Air Care Colorado :: Independent Test Centers

[SANDOVAL]

Update to the post.

Went today to get it tested. I was in and out in 15 minutes they did a sniff test for 2 minutes in 2 rev speeds and that was it. No questions about thermal reactors or pumps, etc. They were perplexed as to why it has 02 sensors on the headers. I said well it's modified... "Is this the original engine?" Me: "Oh that, no this car is modified see that is all fuel injection parts and that intake is supposed to be black...they did not come red like that from the factory" Tech: Oh so that explains the 02 sensors. Me: just shook my head up and down

It passed and I'll grab my collector plates and not have to go through that process again.

[kevin930t]

One hell of a hot rod you have..

Sent from my SM-N910T using Tapatalk

[JacobS911]

Wow congrats on getting passed! It was a pain on mine when I went through this the summer before last. They failed me for holes in my exhaust.. they were the holes in the heat exchangers to get the socket extensions up to the header nuts.. idiots. then they said no air pump and no cat. Pointed out the cat, but of course I don't have a air pump. Took it to the emissions check in Golden. Didn't even lift up the lid.. put it on the sniffer and passed me. Luckily the guy who did it was cool about it and my story.. Would love to check this thing out asap!!! Shoot me a PM! Looking for more Porsche buddies to get some drives in with! Car is beautiful!

[Walt Fricke]

Jacob - the Rocky Mountain Region of PCA has a pretty active weekend meet/drive program. Go to the website for info. You will meet lots of folks that way.

[juanbenae]

that's pretty good. id save the test guy you used today on speed dial so next time you need to smog it you can directly there. I'm sure the emissions from the more contemporary motor were waaay less than what the state has on hand regarding a 76 model.

here in CA they would make this a huge issue having to get a "referee" to look over the car to declare the motor swap. then! require it to meet 91 standards moving forward every couple years. they are called C.A.R.B, California air resource board and they are bastards...