Diagnostic Aids
WARNING: This page is about a different car, the 2001 GMC Savana, 2001 Chevrolet RV Cutaway, 2001 Chevrolet Cutaway, and 2001 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
Inspect for excessive deposits on EGR pintle or seat. Remove EGR valve and inspect for deposits that may interfere with EGR valve pintle extending completely or cause pintle to stick.
If an intermittent is suspected, see INTERMITTENT TROUBLE CODE DETERMINATION under ON-BOARD DIAGNOSTICS under SELF-DIAGNOSTIC SYSTEM.