info on egr and air

[mrcarter]

i have a 99 ta. Next step is exhaust. I dont have the ls6 intake on yet, but I will. Im gonna make the jump to a fast. I will be putting a cam in also. Plan on pacesetter lts duals and dumped before the axle. Question is, Can I eliminate the egr on the headers. Also the air fittings if so, what steps do I have to take to make sure everything works out in the end.

[0rion]

yep, just pull it all off and cap anything that's left open. You didn't say if you were getting pacesetter emmissions style headers or race style. If emmisson style you'll have to use block off's on the egr and air ports on the headers, if race style you will not. The egr hole in the ls1 intake can be blocked with a 1 3/8" adjustable freeze out plug that you can get at any parts store. After everything is done you'll have to get the codes turned of with a tune or your ses light will be on.

[mrcarter]

i understand why you dont need the egr. but what about the air ports. what is the reason for blocking off the air?

[0rion]

the air pump injects air into the exhaust stream to help get the cats up to efficiency faster. Most people doing header swaps are losing the cats anyhow so there's no need for the air pump and the thing weighs probably 15 lbs. It's behind the drivers side headlight. There's really no performance gains to be made by losing either, just cosmetic more than anything else and a small weight savings.

[mrcarter]

the egr can be plugged off and the air connectors can be pulled right out of the car? But a tuner must eliminate both off with a good tune correct?

[0rion]

the only thing they have to do is turn the codes off. There's also a table in hptuners for egr correction you turn off that pulls some part throttle timing. When I pulled my egr hptuners wasn't out yet and I used edit and the old way of calculating what timing cells were being referenced and pulled timing that way. Hptuners simplified that quite a bit. If you don't reduce the timing in those cells you'll see some tip in knock.