Hi All,
Just a short tip on an EGR valve repair.
Couple years ago got a '95 minivan with a 3.8L in it. When I took it through emissions the Nox was sky high. Check engine light was not on. I replaced the EGR valve with a new one and it then passed emissions fine.
Being the packrat that I am I threw the defective valve in my junk box instead of in the garbage.
Last week the check engine light went on and stayed on. I put a scanner on it and got a "defective EGR valve" code.
Suspecting that the problem was the EGR solenoid (ie: an electrical fault that the computer could actually detect) I took the EGR valve off and fished out the old defective valve from the junk bin. I took both valves apart and took the good, intact rubber diaphram from the "new" valve and used it to replace the old cracked leaky diaphram in the "old" EGR valve. I then put the old EGR valve back on and wha-la: no more check engine light.
So the tip is if your EGR valve goes bad and you have to replace it, hang on to the old valve. Looking at the valve it seems to me there's only 2 parts that would fail, either the diaphram or the solenoid, it would seem to me that it would be unlikely that both would fail at the same time. The valve is easy enough to take apart to see if the diaphram is cracked and leaking.
Ted