Just finished header install and not happy with EGR and AIR hookups. Fittings did not match up so I cobbled something to get by. It seems to work but doesn't look very good. What all is involved in completely eliminating these from my 93?

 

Not much is involved. Just remove the stuff, then plug/patch any holes left. Check out this page, it has guides/illustrations for it:

http://www.projecttransam.com/Projec...t&Search=False

I guess just copy the link then paste it in the browser address bar.

 

can someone tell me the benifets and problems associated with the !EGR and !AIR ??

 

!EGR can eliminate the risk of the dreaded LT1 intake manifold leak, and can significantly lower underhood temperatures, but you will slightly increase cylinder temperatures and allow more hydrocarbons into the air to **** of the EPA.

!AIR simply does away with all that extra plumbing in the engine bay, and allows MUCH MUCH more room for work. I can't stress how much better my engine bay looks without it there. It also weighs a few pounds too. Only disadvantages to removing the AIR pump are the resulting SES light (easily cleared via programming), slightly longer time for catalysts to heat up, and once again, pissing off the EPA.

 

do you know if those mods would make a car non-passable for smog in CA??
also any guides to show how to do em?

 

You'd pretty much definitely fail, moreso because of the EGR.

To remove the AIR, all you need to do is, well...remove it. Just unplug and unbolt the air pump from the motor, remove the attached lines (the metal line running underneath the timing cover might be a pain in the ***, so you might need to cut it off), and plug the holes in the manifolds and intake tract. Nothing special.

Blocking the EGR consists of sandwiching a gasket-sized solid plate between two gaskets where the rippled tube from the passenger side exhaust manifold mates with the intake manifold. Here's a diagram explaining it better.

Any more questions, feel free to ask.

 

Ramair, just out of curiousity, what would you have to do to block off the EGR on a 97 OBDII?? Would there be any bad effects?? Is the EGR really all that important?? The reason I ask is because I'm getting the infamous P0400 code ever since I put on the headers. Can I do it without necessarily programming it out?

 

Blocking the EGR on a 97 is just as easy as blocking it on any other model. You just need to make the proper size plate, and sandwich it between the rippled tube and the intake manifold on the back passenger side, like shown here.

The actual purpose of the EGR is to lower combustion temperatures and reburn exhaust gases to lower the amount of NOx released into the atmosphere. It won't hurt anything to remove it.

The P0400 code won't go away unless you have it cleared out. Blocking it alone with even a functioning EGR valve would still set an SES light. You don't need to program it out, but that SES light might get a bit annoying, and could mask other SES lights, since it only has the function to display one fault.

 

What happens depends.... on whether its OBD-I or OBD-II.

Remove the AIR in a 93-95 and all you need to do is make sure there is a good fuse in the circuit. No code/no SES.

Remove the AIR on a 96-97 and it knows its missing because there are flow detectors. Usually has to be programmed out.

AIR has no effect on WOT. It only opereates for a few minutes at startup.

AIR has little effect on emissions testing, because they typically don't test it in a "cold start" condition. Code and SES will be set.

If you need to pass a "visual", they might notice if the pump is missing.

As far as EGR, both OBD-I and OBD-II use a test to determine if MAP varies when the EGR valve is supposed to open. But the OBD-I test isn't very sensitive, and usually doesn't set a code. But it can happen. The OBD-II test is too sensitive, and programming it out is about the only way to go. I have seen some posts by someone who claims to have a "sim" for EGR delete, so you might want to do a search.

If you disconnect the EGR solenoid in either OBD-I or OBD-II you get code and SES. You could use a resistor to simulate the load of the solenoid.

EGR is not used at WOT, so it has no effect on performance. If the valve is leaking, however, it will cause stumbles and surging.

EGR can be beneficial, because it is used to reduce NOx (not HC's) when the engine is under part throttle conditions that cause elevated combusion temps. The exhaust gas replaces oxygen and "quenches" the combustion temperature. This not only reduces the formation of NOx - so it MAY affect whether you pass rolling emissions- but it also reduces the tendency to detonate when lugging the engine.

 

My car is also OBDII and there are no bad effects. No the EGR is not important. My SES light WAS on due to the fact that after my header install:
1. AIR pump is gone
2.EGR is one
3.Cats are gone

But after I put my LT4 KM in my PCM friday my SES light is gone. I understand that my battery was unplugged for about 20-25 min since I was taking my time and the computer resets itself, but I'm a bit confused why my light's gone .