Excessive Exhaust Emissions (Odors)

SYMPTOM DESCRIPTION:
Vehicle fails an emission test. Vehicle has excessive "rotten egg" smell. Excessive odors do not necessarily indicate excessive emissions. For further diagnosis by symptom and testing of emission components refer to EMISSION CONTROL DEVICES.



SYSTEM OR COMPONENT TO CHECK ACTION

COOLING SYSTEM Check Overheating:
- Cooling System for low coolant.
- Cooling Fan for proper operation.



FUEL Check System running rich,
(block learn less than 115)
and possible DTC 45.
System running lean,
(block learn greater than 150)
and possible DTC 44.
Properly installed fuel cap.
FUEL PRESSURE





EMISSIONS CHECK EVAP system canister for fuel loading.
CATALYTIC CONVERTER For lead contamination
of catalyst (look for the removal of fuel pipe
restrictor).
PCV SYSTEM for being plugged, pinched,
or blocked [1][2]PCV hose, or fuel in the crankcase.
EGR SYSTEM Valve not opening.




IGNITION CHECK Incorrect timing or excessive advance.
Spark plugs, plug wires, and ignition components.





ENGINE CHECK Vacuum leaks.
Fuel in crankcase.
Carbon build-up. Remove with top engine cleaner.