Initial Inspection and Diagnostic Overview

SYSTEM INSPECTION
^ Visually inspect the components of the Exhaust Gas Recirculation (EGR) system.

^ Mechanical
- Loose, leaking, or damaged vacuum lines.
- EGR valve stuck open.
- EGR valve attaching bolts loose or missing.
- EGR valve flange gasket damaged or leaking.

^ Electrical
- Damaged connectors.
- Damaged insulation.
- Damaged components that affect EGR.
- Damaged EGR components.

^ Exercise the wiring harness and connectors for the EGR components. Check for looseness, corrosion, or other damage. This must be done after the engine reaches normal operating temperature for activation of all EGR system components.
^ Check the vacuum lines and connections for looseness, pinching, leakage, splitting, blockage, damage, or liquid contamination.
^ If the vehicle system inspection is OK, proceed to the Pinpoint Tests. Pinpoint Tests