My parents took their 2001 Pontiac Bonnevile SLE to the garage when the "Service Engine Soon" (SES) light illuminated. For $400 the garage said they would replace the EGR valve.
Well, I decided to do it myself for $150 (valve, gasket and shipping).
It is an easy change out. Surprisingly, the SES light remained lit. This raises several questions:
Is there a seperate manual procedure to extinguish the SES light? If not, does this suggest that there are other problems. If so, is there an OBD code display that will help in IDing the problem?