EGR removal from TPI

I want to remove the EGR valve from my tpi.
I am not worried about if my car is going to pass emissions or not. I was wondering what was involved in doing that, how it would effect the computer and what kind of gains would it make?
thanks for the help!

Dont know what it will take to take it off but you will have to have a chip burnt for it if you do.

If you want to make any gains at all, you are going to have a chip burnt even on a stock engine. I would recommend www.fasterproms.com because they did an excellent job for me. I got it dyno tuned by them. Of course, the road was my dyno.

Since the EGR is actually nonfunctional in upper RPM, you will see no gain and go on to pollute the air that much more. ;)

Unless the EGR valve or circuit is faulty, or the EGR passages are blocked, you are throwing money away. Even though EGR does contaminate the intake charge a little, it allows more ignition timing advance. More advance means better throttle response, better gas mileage, and more power. Not to mention you'll have to buy the gaskets for the plenum just to get at it. And then you'll need a PROM burned. It's not worth it.

Unless the EGR valve or circuit is faulty, or the EGR passages are blocked, you are throwing money away. Even though EGR does contaminate the intake charge a little, it allows more ignition timing advance. More advance means better throttle response, better gas mileage, and more power. Not to mention you'll have to buy the gaskets for the plenum just to get at it. And then you'll need a PROM burned. It's not worth it.

I thought it does all these wonderful things only on cruise mode?

It allows the engine bay to be a little cleaner and you can reuse your old gaskets provided they don't break up on removal. I have resued some air gaskets but never ones that flow liquids.

You are going to want an EPROM to take advantage of any mods you make anyways. Even if the system is stock, you will see some good gains from a tune.

I second the benefits of a good tune.

3.8TransAm on TGO saw a 14.4 @ 98mph with a 2.4 60ft in his 1991 GTA 5.7L TPI. He's got a custom prom he tuned with a narrowband 02, and a cat back.

The day he ran that 14.4 there wasn't any traction compound on the track because we couldn't afford it, it was 90* outside, and the humidity index was 85 to 90%!!!!! With good traction on a good day that could be a 13 second car!!! Thats damn good on street tires with no suspension mods, and just tune and cat-back!!!

Thats enough to shock the hell out of a cocky LT1 owner and make them think twice about TPI. Though LT1 induction and the heads are still better on those cars...... grrr...... nice flowing heads and intake from the factory would be cool.

I thought it does all these wonderful things only on cruise mode?

Right, it does. If I was talking about WOT performance I would not have mentioned gas mileage or throttle response. Maybe I should have said "torque" instead of "power".


It allows the engine bay to be a little cleaner and you can reuse your old gaskets provided they don't break up on removal. I have resued some air gaskets but never ones that flow liquids.


Being a professional technician by trade, I never reuse gaskets, regardless of their function. Even on low mileage new cars, its good insurance. I've had bad luck trying to shortcut jobs and reuse gaskets and certain types of fasteners. I don't like comebacks.

I would like to bump this aging thread because I am hungry for more info...

I just bought my '88 IROC, 305 TPI...and I noticed that the previous owner had removed the smog pump, but left the EGR stuff. Is this going to creat any vaccuum leaks? I'm troubleshooting a rough idle and hot plugs (ashen white is more like it), and I'm thinking I have a nasty vaccuum leak somewhere...and I'm thinking the culprit is in the half-removed EGR system.

Any suggestions?

The EGR, and A.I.R systems are completely seperate. Removing one system will not cause a leak in the other.

To remove the smog A.I.R equipment you need to remove the smog pump, associated tubing, manifold air tubes (you can buy caps to plug them from a parts store), and then you will need to cut and cap the tube running to the cat if you have a 3 way catalytic converter. All TPI cars had a 3 way cat-converter.

You will also need to reroute the belts with a shorter one if you have a serpentine setup. This has been discussed numerous times on Thirdgen.org.

Yeah, shortly after posting this question here and in another thread I discovred thirdgen.org. :)

As for what you are saying, I bought the car with the smog pump gone, but I'm not sure what else he ad done...I know the tubing and the cat are still there (not plugged) so I got at least some work to do to get it up to par. Thanks!

Yeah, shortly after posting this question here and in another thread I discovred thirdgen.org. :)

As for what you are saying, I bought the car with the smog pump gone, but I'm not sure what else he ad done...I know the tubing and the cat are still there (not plugged) so I got at least some work to do to get it up to par. Thanks!

That is an issue. If the tubing is there, it might be sucking in air and I would not like that. If you want to do it, take the check valve out of the manifolds and plug them up. If air gets into the check valves and then inot the manifold, it might contaminate the charge going to the O2 sensor and give it a false reading. Not sure if it would but it would be easier and cleaner to plug it up. As far as the cat goes, cut off the pipe and weld the hole shut and you are fine since you don't have an AIR pump to blow the cat anyways.

True, I should have written my statement better.

Removing the smog system will not create a vacume leak in the EGR system, but at the same time you must seal the AIR tubes or it can cause problems with the O2 sensor, and the operation of the cat-converter.

Me thats not a problem. I don't have a cat, and I don't have to worry about emissions. :D

Thanks all for the replies.

Would all these tubing sucking air generate a lean condition? When I recently changed the plugs, they were ashen white, indicating overheating/lean conditions..hoping that the clean air being introduced into the manifold vice half spent exhaust gasses is what's causing it.

I'm registering the car in Florida even as we speak, so there should be no problem with emmisions. I'm gonna leave the cat on for simplicity's sake with the 5.0L, but when the new engine goes in, the emissions go out. ;)

Couldn't white be coolant too?

Actually it would generate a rich condition if you left the driver side AIR tube uncapped. More air would go in and the O2 sensor would report that the exhaust is lean and richen up the mixture.

But isn't my car metered by MAF? If the MAF isn't detecting the extra amount of air going through it, because it's coming from another source, then how can it properly meter the amount of fuel? The 02 (without being broadband) is less about metering and more about general failure of the engine (extreme rich/lean), but the engine could still be slightly off-kilter (enough to show up on the plugs) and the o2 not pick it up.

I'm speaking only from experience of tuning a single turbo Supra, which may be another world altogether, but that beast ran 8:1 AFR when I had a monumental boost leak in it, the o2 didn't lean anything out at all, because the MAF was metering huge amounts of air, the ECU was dumping huge amounts of fuel.

Well, in the program you write in a correction factor. Lets say you figure 300 cu ft of air coming in, you just figure on it while writing your program. Also, on it's own, the ECM has a window of correction too.

Not quite sure what you are saying there aklim...