I have a 97 Buick LaSabre with 93,000 miles. The check engine light came on and the mechanic said the reading was due to insufficient air flow at the egr valve. He reset it, test drove it, and said that the valve may need to be cleaned if it came on again. (He is a great guy and didn't even charge me for the service.)
After a few hundred miles the light came back on. I purchased a code reader of my own and found 2 readings. Both were insufficient air flow at the egr valve. I deleted the codes and went several hundred miles again before the light came on. I removed the valve and cleaned it as best I could and replaced it with a new gasket. Several hundred miles later, same thing. Always the code is entered twice.
I have noticed that when the light first comes on it is as I start to decelerate. Due to increased vacuum, I assume.
My NAPA dealer lists a replacement gasket that has a screen.
Now my questions:
Does the computer start checking for this condition immediately after being reset?
Should I try replacing the gasket with one with a screen $18.75 vs $2.50 before replacing the valve?
Is there something besides the valve that could be causing the problem?
Should I just bite the bullet and replace the valve?
If I replace the valve, do you recommend using the gasket with a screen?