Bypassing smog pump?
 

Hi. I have a 1992 Z28 with a 305 TPI and was wondering what i can do to bypass or even take off the smog pump. Thanks.

eighther get a delet pulley for it or open it up and gut the pump and just use it as the pulley. they say you can also just rerout your belt so its not on the pump but i wouldnt do that.

Depending on where you live, you might be able to still pass inspection without it. If your state does an underhood visual though, you gotta keep it.

You can remove the smog pump all together, and anything that attaches to it. There is a black pipe attached to the back that leads to a black box, that can all go. You are going to need a belt that is a different length, I can't remember what it is, but you can check in the tech threads on the home page. Either that or take a string and route it the way the belt would go, and mark it where it overlaps. Then, measure the length and go to an autoparts store. The part number for the belt is the length of the belt in inches. So if you purchase a P925, its 92.5" long. At least thats the way that duralast does it.

IIRC 66" belt

IMHO if the system is in good shape and working correctly then theres really no good reason to remove it unless maybe you have headers

its alot of work to get the tubes and fittings off the exhaust and they are good at breaking off/stripping


i normally dont remove an AIR system unless a tube is broken off or if the pump died or something else bad, etc

not worth the effort otherwise

good luck

You can do all that I mentioned and still leave the AIR tubes hooked up. I would actually recommend that he leave those on until he gets headers.

Getting rid of the smog system is not about gaining power or reducing weight (although the pump itself weighs a good 10 lbs, and if you swapped headers, thats another at least 20 pounds gone), it's mostly about cleaning up the engine bay and making everything more easily accessible. You know there's guys on here that post at least once every other week asking "How long does it take to change your plugs" or "whats the easiest way to change my sparkplugs with all this crap in the way". To some people with a stock motor and everything still in place, it can take them hours if they don't move anything. With the smog crap gone, it takes me no more than 10 minutes.

Is that the belt i would need if i pulled the whole system out? Or, with using a delete pulley? Thanks. I want to remove all of it. Here in Kansas, we have NO tests or anything. When i bought it from out of state, the inspection consisted of checking the odometer and numbers. That's it...lol

Sweet, have at it then. Some people don't like the idea of removing the equiptment and making mother nature mad, but in all actuality, you can still pass the sniffer test easily.

I have a 1989 GTA and i took my pump off and it sucked, because there are Torx bolts and you have to be careful not strip them, i think they take T40. I used a 6 ribbed belt 98.0" long. I still have my exhaust tubes still in but the two hoses to the AIR module(black box) or plugged by bolts now. You just have to play with the belt length, as i had to make several trips to AutoZone. It cleans up the engine bay extremely, now i can see my passenger side valve cover, exhaust, etc. The reason i deleted my pump was because it the pulley was shaking and wobbling and the pump was very dead.

So, i have a 66" belt and 98" belt? Guess i will take it apart and figure it out. Thanks!

It's not gonna be the 68" Belt, I can tell you taht for sure. It's gonna be 90-something.

I wouldn't bypass the pump. I would remove it totally instead. Bypassing the pump might be OK for a short time like at the track. What happens is that the checkvalves leak slightly allowing some exhaust gas to push backwards though all those delicate parts and into the pump. The whole mess will eventually freeze solid ruining everything including the pump, control valves and check valves.

When the pump is running, it generates enough air pressure to keep exhaust gas out.

Ok. So i am going to remove it completly. Another question is can i remove the cat? And do i need to do anything to the computer when removing all this stuff? Thanks!

It's actually a 96.8" belt.
You can remove the cat. Illegal like removing the smog pump. Nothing needs to be changed in the ECM.
https://www.thirdgen.org/serpentine Dayco part number included in here.
Napa part number 25-060966. 96.6" belt

I tried to use that 96.8 belt and it was way too short, but you can try it because it might be different you just have to play with the length. The smog pump module only gets electricity from the computer not any important info. just elec.

I just did mine a couple weeks ago and a 98" belt fit mine perfect.

fits both of my birds perfect as well. If it doesn't fit then it's either routed wrong or there are assembly differences from GM.

Re: Bypassing smog pump?
 

I just wanted to add my 2 cents here. I got my 1992 Firebird GTA from my brother, who had already had the catalytic converters removed when they collapsed years ago. Recently the smog pump started making an awful clicking noise. I figured I don't even have a catalytic convert, why even have the smog pump? I looked at the tech article on how to remove it. If you just take the pully off, you still can't route the belt around it because the actual device protrudes a bit and will rub against the belt pretty bad. You'll have to remove the part completely. It was super-easy, I had it off in less than an hour, and my car sounds beautiful once again.

Re: Bypassing smog pump?
 

im in same boat that you were....took the pulley off b/c it was locking up/freezing and thought I could just run it like that....... how wrong was i??? ive just been too lazy to take it out and havent really run it much lately haha