Diagnostic Aids
WARNING: This page is about a different car, the 1997 GMC Savana, 1997 Chevrolet Chevy Van, and 1997 Chevrolet Chevy Express. However, it is still accessible from the selected car via links, so may be relevant.
Inspect VCM connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals and poor terminal to wire connection. Inspect wiring harness for damage. If connections and harness are okay, observe scan tool while wiggling related connectors and wiring harness. A change in display will indicate location of fault.
If EGR valve indicates signs of excessive heat, check exhaust system for blockage (i.e., plugged converter). If exhaust system is restricted, check for possible open injector cause by grounded driver circuit, injector stuck open or faulty VCM. If problem is not found, check oil for possible fuel contamination.