EGR Maintenance

The EGR valve on the intake manifold must be removed, cleaned and inspected at the mileage intervals as specified. The exhaust gas passages in the intake manifold also should be inspected and cleaned as required.
After cleaning, open the EGR valve manually by pressing down on the pintle, then release. If the valve does not return to the fully closed position, it must be replaced.
Inspect the exhaust gas inlet and discharge passages of the intake manifold for any restriction caused by carbon or lead deposits.
On six cylinder engines, lead or carbon deposits build up rapidly in the exhaust gas discharge passage upper hole. If the deposits cannot be removed a 9/16 inch drill bit may be used.