The vaccum control valve above the EGR valve has a hole burned in it. Can I by pass it or do I need to replace it.  I can only find part at dealer for $146.60  I would like other options.

what are we working on 

$25 shipped. Good used.

The EGR vaccum control valve problem is in a 1994 sidekick. I found one on E Bay for $ 25.  But would still like to know if removal of that system could help with performance and milage.  Also what can i do with the air intake ?  I would like to remove everything and put a K&N type filter on,  but the mass air flow and the water cooling lines are comfusing .  can I plug the water lines and move the mas air flow sensor? My goal is to get best milage possible.  Thank you for your help.

If anything, changing the existing intake system will make mileage worse!

Since you said it was on a Sidekick, you might also consider cleaning the tubing that runs from the EGR valve. This passage usually gets clogged with carbon causing OBDII PO400 errors. Replacing EGR components won't be of much use without cleaning out this passage first.

Check out this link for more info:

http://www.rottenbob.com/x-90/p_egr.html

(Found by a search for EGR at Ack's FAQ - see signature for link...)

Adding a K&N filter is a different thing altogether!  You should be able to break into the fresh air intake at the Filter box outlet thus bypassing (and removing!) narrow intake "plumbing" that meanders through the inside of the passenger-side fender... Or so I recall..

I hope that this helps!