Emission Control Systems: Service and Repair

Intake Plenum Service:

EGR AND INTAKE MANIFOLD PASSAGE CLEANING

EGR And Solenoid Service:

NOTE: The air intake plenum must be removed in order to access the EGR valve.

PLENUM AND EGR REMOVAL:

1. Disconnect negative battery cable.
2. Disconnect throttle, T.V. and cruise control cables. Remove cable retaining bracket.
3. Remove the 4 throttle body retaining bolts.
4. Disconnect Throttle Position Sensor (TPS) and Idle Air Control (IAC) valve electrical connectors.
5. Remove right intake air runner.
6. Remove air plenum retaining bolts.
7. Remove plenum and gaskets. (discard gaskets)
8. Remove EGR vacuum line.
9. Remove EGR retaining bolts.
10. Remove EGR valve.

INSTALLATION

^ Install in reverse of removal.


EGR VALVE INSPECTION AND CLEANING

CAUTION: If EGR passages in the inlet manifold indicate excessive build-up of carbon deposits, the passages should be cleaned. Care should be taken to ensure that all loose particles are completely removed to prevent them from clogging the EGR valve or from being ingested into the engine. Do not use chemicals or solvents to clean the EGR valve or intake manifold passages chemicals may cause damage to system.

Clean EGR and passage as follows:

1. With a wire wheel, buff the exhaust deposits from the mounting surface of the EGR valve and around the valve.
2. Look for exhaust deposits in the valve outlet, remove deposits as needed.
3. Clean intake manifold mounting surface.
4. With a suitable tool clean EGR passages in intake manifold, blow ports clean with compressed air.


POSITIVE CRANKCASE VENTILATION (PCV) SYSTEM INSPECTION


Maintenance of the PCV system consists of inspecting the hoses to make sure they are clear and in good operating condition. The vacuum orfice, in the intake manifold, should be inspected on a regular basis to prevent the hose from being plugged.


MAINTENANCE SCHEDULES



Every 30,000 miles (50,000 km)

Fuel Tank, Cap & Lines Inspect
PCV Valve Inspect
Spark Plugs Replace
Spark Plug Wires Inspect
Engine Timing Check

Every 30,000 miles (50,000 km) or 24 months

Engine Accessory Drive Belt(s) Inspect
Cooling System Service/Inspect

Every 30,000 miles (50,000 km) or 36 months

EGR System Inspect
Engine Air & PCV Filters Replace