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

Fuel metering ^ Check air/fuel ratio, (02 sensor voltage).
^ Perform injector service, (cleaning).
^ Check fuel pressure (check vacuum line and return hose). Fuel Pump Functional Tests

Faulty fuel cap Replace fuel cap

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

Poor or contaminated fuel ^ Check for excessive alcohol content
^ Recommend higher grade fuel
^ Drain fuel tank and add clean fuel