exhaust back pressure

[rrhayden]

exaust back pressure

I have been having idle issues for the past month or so. When warm, at a stop light, the engine will surge to about 900 rpn, the settle back down. There has been no service engine light. Last night while ideling in traffic the engine got HOT I managed to get home with out overheating. Reading my manual, the egr can cause overheating. I tested it, by pulling it in while ideling and the engine stumbles and sputters, the thing I noticed was there was a back pressure trying to push it closed, could I have a restricted exaust / cat ? If so how do I diagnose it?
Thanks
Ron

 

[Dave C. '04 Z06]

EGR valve

It has a spring in it that pushes it closed. Are you sure this isn't what you were feeling?

-Dave C. '97 Z28

 

[rrhayden]

Dave,

I will check again, however it felt like there was pressure building and it was being forced closed. Not the spring

 

[grumpyvette]

is exhaust back pressure killing performance ?MAYBE, BUT ID LOOK ELSWARE FIRST, IF YOU FIND NO OBVIOUS PROBLEMS HERES HOW TO TEST
its a fast easy test that needs to be done and more than a few cars running older cats are having a restricted exhaust thats hurting your performance badly, and because the problem tends to build up slowly many people don,t notice the gradual power loss
first thing youll need to realize is that the TEST POINT needs to be after the header collector and in front of the CAT AND MUFFLERS. next thing you need to know is that to get a valid answer youll need to have a long connector hose so someone in the pass seat can CLOSELY WATCH the gauge as you accelerate under load (FLOOR THE CAR THRU THE FIRST 1-2 GEARS and watch the pressure surge. readings above 1psi mean somethings partly restricted, readings above 3psi are hurting your performance BADLY
the test kit is about $50.00 http://www.jdsdiagnostic.com/eptspage.htm
ITS NOT RARE TO LOOSE 20% or more of your hp to a restricted cat

 

[rrhayden]

Thanks for the info, I am thinking somthing must be plugged and will check this weekend. I read that you can remove the conection to the air check valve and test there do you agree?

Thanks again