Initial Inspection and Diagnostic Overview

1. Visually inspect components of the Exhaust Gas Recirculation (EGR) system:

Mechanical
- Loose, leaking, or damaged vacuum lines

- EGR valve stuck open

- EGR valve bolts loose or missing

- EGR valve flange gasket damaged or leaking.

Electrical
- Damaged electrical connectors or insulation

- Damaged components that affect EGR function

- Damaged EGR components.

2. Exercise EGR component's wiring harness and connectors. Check for looseness, corrosion, or other damage. Do this with engine at operating temperature for activation of all EGR system components.

3. Check vacuum lines and connections for looseness, pinching, leakage, splitting, blockage, or liquid contamination.

4. If system inspection is okay, see EGR Pinpoint Testing. EGR1 - Check EGR Control Solenoid