Initial Inspection and Diagnostic Overview

1. Visually inspect Exhaust Gas Recirculation (EGR) System components. Check for:

^ Damaged connectors.
^ Damaged insulation.
^ Damaged components that affect EGR.
^ Loose, leaking, or damaged vacuum lines.
^ Poor driveability during engine warm-up.
^ EGR valve stuck open.
^ Loose or missing EGR valve attaching bolts.
^ Damaged or leaking EGR valve flange gasket.

2. Exercise wiring and connectors for solenoids and other EGR system components for obvious problems due to looseness, corrosion, or other damage. Do this with engine warmed up.
3. Check vacuum lines and connections for looseness, pinching, leakage, splitting, blockage, or other obvious cause of malfunction.
4. If a vacuum line or orifice (restrictor) is suspected as the cause of a malfunction, repair the problem before proceeding to the next step.
5. If all checks are OK, proceed to Pinpoint Tests.