egr valve
 

replaced egr valve 3 weeks ago. service engine light back on showing same code as before egr valve. How do I know if this new part is defective? any ideas or suggestions on this problem would be greatly appreciated.

Welcome to the forum. Please provide more information about your car. Like year, model, mileage, etc.. To be honest there probably nothing wrong with your original egr valve if the replacement set the same code. Auto parts store code readers sell lots of parts but rarely solve the root issue. With more information we can usually help solve your repair issues.
Andy

1996 SL1 162,000 miles

Could we get the codes that led to egr valve replacement. Derf has the fsm set for the S series cars. I have an L series set, I may need to acquire a Vue set unless someone here has one. Bonestock is the Ion goto guy. Rube has years of experience that he gladly shares. There are many others here also!

Any chance you kept the old one?

I guess bert will never be heard from again.

I bet his CEL is still on.

Too much carbon build up in the inlet pipe. Will hang up a brand new valve pretty damn quick -- doesn't take much. There is one code that I had where no matter what you do, the fully open and closed V's don't match those stored in the PCM from when the car was built. There are only a few ways to trigger a relearn for the damn thing. One is classic backyard engineering voodoo and works like a charm. The other requires PCM reflash and no guarantees because the new values are pre programmed and not always relearned.

Whatever