Excessive Exhaust Emissions (Odors)

Definition: Vehicle fails an emission test. Vehicle has excessive "rotten egg" smell. Excessive odors do not necessarily indicate excessive emissions.

POSSIBLE CAUSE ACTION


Incorrect idle speed ^ Check Idle Air Control (IAC) valve. Refer to COMPUTERIZED ENGINE CONTROLS/DIAGNOSIS AND TESTING PROCEDURES/DIAGNOSTIC CHARTS.
^ Check Minimum Idle Air Rate. Refer to ADJUSTMENT PROCEDURES/MINIMUM IDLE AIR RATE.


Fuel in crankcase ^ Determine cause (flooding, excessive cranking etc.)
^ Change oil and filter

Fuel Metering ^ Check air/fuel ratio, (Verify O2 Sensor Voltage), refer to COMPUTERIZED ENGINE CONTROLS/DIAGNOSIS AND TESTING PROCEDURES.
^ Check fuel pressure, refer to DIAGNOSTIC CHARTS/FUEL SYSTEM PRESSURE TEST (CHART A-6).

Faulty fuel cap ^ Replace fuel cap

Lead contamination ^ Check for missing fill pipe restrictor
of catalytic converter ^ Replace catalytic converter if contaminated.

Poor or contaminated fuel ^ Check for excessive alcohol content, refer to ALCOHOL-IN-FUEL TEST.
^ Recommend higher grade fuel
^ Drain fuel tank and add clean fuel, refer to MAINTENANCE PROCEDURES/FUEL TANK DRAINING.