i have been lookin at intake manifold and they say with or without egr, what is egr and how do i know if i need an egr or non egr manifold? thanks

 

Exhaust Gas Recirculation.

It is an emissions control system that lets a little exhaust back into the intake when the engine isn't under a large load, like when cruising, to reduce cyl pressure and therefore NOx emissions. It is necessary on some stock motors to allow the full ignition timing advance to be used. Without it, you may get spark knock.

If you are retaining your computer controls, or if your locale has a visual emissions inspection, get one with it. Otherwise, you can do away with it.

 

Also, Check this out:

https://www.thirdgen.org/newdesign/t...diagnose.shtml

This is from the technical articles page on this site which is here:

https://www.thirdgen.org/newdesign/tech/

Got some time? Read them all, they cover just about all the basic knowledge you should know about your car.

Also, use the search function on this forum when looking for answers to broad questions like this one. This question has surely been asked before and if you find that post, you can rest asured that the answer is still correct.

Keep On Keepin' On