alright im getting the motorsport aerospace coated header for my 75 280z with FI and was wondering since the egr will no longer be able to connect into the exhaust system will the car still run? or does that mess up the computer somehow so that it wont run?i dont have any idea and its really bothering me so any info would be great thanks

My 78 has a header on it and the EGR valve doesn't have the tube on it. I don't know why theEGR valve is still on there. I think I'll take it off and J.B. weld a plate over the hole. Same with the thermal vacuum valve and the baqckpressure transducer valve. I don't know what they do tho.

I think the EGR valve just lets some exhaust gases back into the intake, so if you remove the EGR valve, you will have to adjust the AFM, because it will be running rich? Maybe some cool, clean air instead?

Tomohawk, I don't know if it would be that simple. Remember, when you push up the diapraghm in the EGR, the engine dies. If you plug the opening in the manifold wouldn't that be basically the same thing?

I would have to try it and see. Thx for the heads up.

well when i took my car in for a diagnostic nissan said it was running too rich already and i dont know anything about FI so i didnt know how to change it but anyway so if you leave the egr on it the car will still run even tho the egr goes nowehre thats nice to know and if you try taking the egr off and plugging that hole on the manifold tell me what happens thanks for the info, oh yeah back to the runnning rich thing how do i correct that?

When I got my engine the look-over at the dealer, he said "you're running rich" (off the scale!?) You can do these things:

1. Replace the AFM (obviously not working)

2. If not the AFM, then replacethe wiring for the engine.

3. If not #2, then replace EVERYTHING.

The AFM from the edealer runs $600 installed. No guarantee that it will fix the problem, either.

:~(

egr reciculates exhaust gas back into the intake after the mafs so it doesnt affect ur air/fuel readings. The egr opens up at a certain tempurature to lower temperatures in the combustion chambers to keep the nox level low. It is for emissions and the egr on our cars dont have any electronics hooked up to it so the computer doesnt work with it. It works on vaccum. and thats wat the thermalvaccum valve is for. at a certain temperature. it opens up and allows vaccum to the egr and opens it up.

Wont be a problem to remove it and plug it up. Because its jus a hole in the manifold w/o the egr there. When u push up on the diaphram on the egr, it opens the valve so that exhaust gas gets thru to the manifold, thats wat causes it to want to die out.

So if you took the EGR tube from the exh. manifold and had fresh air go into it, then it would be OK? I think mine might already be sucking in the hot air from the engine compartment (no EGR tube is there).

I would have to drain some coolant to remove the thermal vac. sensor, & then plug that?

thx.

You can just disconnect the vaccum lines that go from the egr to the manifold. That way the egr never opens. Then jus plug that vaccum line and it should fine. Im tryin to completely remove my egr to make the enginebay look a little less messy. Im either gonna plug the coolant lines or jus bypass the themalvaccum valve.

Me too.

It means less metal to clean & polish, more room to work, it'll stay cooler & I might even blast the word "Ferrari" on the intake & rocker box!

Wait-- If there aren't enough gadets & thingys on the engine, do you think the "Emmissions Police" will get suspicious?

i doubt that they'll look under your hood, and if they do, they'll prolly notice someting. but then again, isnt ur car already exempt? They only way u'll get in trouble if it is exempt is that he'll send u to the state ref.

I fooled with my egr last summer manually by sucking on the vac hose, and as expected, the diaphram movrf up & let fresh air ( formerly exhaust) in. when I quit sucking, the diapgram didn't return! Is that right? As far as I could tell, there was only the one nipple for vacuum, and there was no way for air to get in to let the diaphram back to close the air valve. I was thinking about drilling a very small hole to let air in, but I'm not sure if there's enough vacuum to move the diaphram then.

I think it would really help if somebody had a graphic of the EGR circuit & hoses that makes sense. I think the thermal vac valve works- at least it only lets air go one way.

thx