One of my catalytic converters is failing, so I'm investigating upgrading to LT's.

One of the decisions I have to make is whether to get headers that include the AIR fitting, or "race" headers that do not.

I know that I can have AIR programmed out of the PCM, but that's not my question.

What function does the AIR system serve? How does it work? Are there advantages/disadvantages to having it? Are there laws I would be breaking if I remove/disable it? I live in Michigan.

I tried searching... "air" comes up a lot, and the search function here isn't case-sensitive.

 

Its part of the emissions system. I'm pretty sure you can't remove it on your 02 but 95 and older don't need to pass emissions anymore so its removed a lot. I have no idea what it does.

 

The AIR (Air injection system) supplys air into the exhaust manifolds during startup to reduce emissions and to help warm up the cats quicker.

 

Michigan doesn't have emissions inspections.

Just raw air, straight out of the atmosphere?

 

Yes. On cold start, the PCM sets a rich A/F ratio. The AIR pump pulls air out of the intake duct, from between the filter and the MAF sensor, and blows it directly into the exhaust manifolds. The air burns the excess fuel in the exhaust gas, to generate heat and heat the cats up faster. The cats don't work until they get hot. IF you do not have cats you do not need AIR.

 

Interesting. So because it's running rich, there's still excess fuel in the exhaust, and because of the AIR system there's oxygen too. What triggers combustion? Just heat from the exhaust?

 

Just the heat.

 

I'm wondering where you got that information. Only cars built before 1976 are exempt from smog. If you are in a CARB state and they know what to look for, you can fail for no AIR system.

 

CARB stands for Califonia air resource board....that may not affect him at all.

hey Green, your car is Cal legal....right???
i know that non of us west coast boys would ever contribute to the smog problems out here....HEHE

 

I'm pretty sure that New York, California, Oregon, and maybe another state or two follow CARB though.

 

true, but there are A LOT of areas in the country that have very relaxed smog laws, so you just need to find out the laws in your area.

there are even places here in california that you can get away with all kinds of stuff. certain mountain and desert areas in cali dont require you to smog your vehicle unless ownership is changing....

 

I live in Mass and 95 and older don't have to pass emissions. Just saying he can get a sticker with no AIR if he takes his cats off...

 

Hey this post is pretty old but it's the newest I could find using the search function. I took off my air pump a while ago and just today the relay started clicking after I shut the car off. Did that ever happen to anyone else? I'm thinking it just a short somewhere. The car is a 94 z28 and my question is if i put true duals on it with dual cats do you guys think I'll pass NJ inspection?

 

The only way the AIR pump relay could "click" is if the PCM (or the wire from the PCM) is providing a ground. 12V is supplied constantly to the relay, not switched power, so its possible for a short on the brown wire from the PCM to cause it to click at any time.

Your car left the factory with one cat. Duals require two cats. Federal law prohibits changing the number of cats or the location. NJ enforces the Federal requirements (and will soon switch to CA standards). IF they look, IF they know what they are looking for, and IF they know your car only had one cat originally, they can fail you. The fact that you have switched to dual cats will not cause problems on the emissions dyno, so they might not even look.

If you have headers, they could also fail you if the headers do not have the CARB-EO emissions tag welded on them.

 

okay thanks man, the previous owner took the cat out so I cant pass but the guys at the state inspection station i go to don't look look at the exhaust as long as you can pass emissions.