Is there a difference between the cars built in California than the rest of the country? Such as far as restrictive emissions? My car was built there 91 LO3 auto, was just wondering if they were some unnecessary hardware I could remove for weight/power purposes.

u can remove the whole air injection system, smog pump air hoses etc. remove catalytic converter. you can remove a/c and the condenser and drier and all hoses. how much weight will u shave off? I dunno maybe 100 lbs..

Now tell him how he is going to pass smog, Sherlock. Of course, you may not have to worry about all that where you are.

By the time 1991 came around the cars built for CA and the rest of the country were virtually identical. The only possible difference might be in the computer chip programming.

Notice he did not say he was in cali, he asked if cars built in cali are different. and what he could do to shave weight, he did not mention smog or california as his state. A S S.

If you take the Cat. off you will have the engine light coming on. I had a custum chip burned from turbo city with all my new engine specs and also told him about the cat. and he burned the new chip so now the light doesn't come on from the no converter situation.

I took my cat. conv. off and do not have any check engine light for it come on. once in awhile i get that code 32 egr, but that's only if i cruise with the engine beloew 1800 rpms for too long..

So then I guess SURVEY SAYYYYYYS... YES, the check engine light does come on. Ding Ding Ding.
Just bugged the crap out of me when it did. How do you know when you have a real problem or it's just that problem over and over? Makes sense to me to have everything working correctly. But that's just me.

but mine did that before the cat conv was off so your survery says no it does not come on for that reason. and i had a new cat on there too before i took it off..

I beg your pardon.

Just so you guys know, there is nothing in the TBI ecm that checks after cat emmisions like the newer vehicles do.....there fore removing the cat will NOT cause a check engine light.

Some people have experienced EGR codes from reducing exhaust back pressure. Some types of EGR valves require a certain amount of back pressure to stay closed. Headers, cat-back's have more of an effect on this than the cat. In fact, a cat that is in good shape will not restrict exhaust flow much at all.

I will back up montes first half of his post.

What it will do is take a hair away fromt he torque, but will gain top-end. Then it will also smell like raw gas.

So when I put my headers and 3 inch exhaust on today I can expect a check engine light? Would a new EGR valve be a good thing to add?

The TBI EGR valve just needs more vacuum to operate correctly, since it uses the exhaust pressure to keep it closed, instead of the TPI valve using exhaust pressure to open it. What my dad has done in the past is carefully drill the vacuum hole in the valve one drill bit size larger. That allows more vacuum to the valve and helps keep the valve closed and the EGR SES light off.

Interesting. Knowledge is always a good thing.

Can I delete these with no side negative side effects?

Converter is going.

Want to keep AC.

The tubes running out of the manifolds, what system are they are part of?

No emissions test here xcept to look and see if a converter is on or not.


"By the time 1991 came around the cars built for CA and the rest of the country were virtually identical. The only possible difference might be in the computer chip programming."


Kevin , do you know what might be different about the programming?

The tubes coming out of the manifolds (actually, they're going into the manifolds) are part of the AIR system, which uses the air pump to pump cool air into the manifolds and the catalytic converter to help with the emissions-reducing process.
Negative side-effects include increasing pollution from your car, and without the cat, having people tell you your car smells bad and its too loud.

I have no idea what specifically is different with the programming, or I would have posted it. I'm guessing there is fuel and timing differences, as well as different durations for controlling the AIR and the EGR valve.

is it worth removing the air injection system and smog pump?

I'm assuming you'd have to plug n weld the holes in the manifolds after removing the tubes.

i removed the smog/ air injection overall not worth it didnt do anything other then make the plugs easy to change the smog compents dont way much its
it saved maybe 10 or 11 lbs total it stinks in the morning until the cat warms up
if i was going to do it again i wouldnt

pluses / engine bay looks much cleaner , plugs easier to change
minuses / smells in the morning/cant pass enspection if you have it and you have to find away to plug the cat
there are othere +/- but i cant think of them right now