Excessive Exhaust Emissions/Odors

SYMPTOM DESCRIPTION:

Vehicle fails an emission test and 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 CONTROLS.



SYSTEM OR COMPONENT TO CHECK ACTION

COMPUTER INPUTS/OUTPUTS CHECK ^ COOLING SYSTEM AND FAN
If a very high coolant
temperature is indicated and the
system is running LEAN.



FUEL CHECK ^ OXYGEN SENSOR
Refer to Testing and Inspection/Procedures.
CHECK: ^ FUEL CAP for proper installation.
^ FUEL PRESSURE







EMISSIONS CHECK: ^ EVAPORATIVE SYSTEM:
Canister for fuel loading.
^ CATALYTIC CONVERTER:
For lead contamination of the catalyst
(look for the removal of fuel pipe restrictor).
^ PCV SYSTEM:
Plugged or stuck PCV valve, blocked [1][2]PCV hose,
fuel in the crankcase, or malfunctioning PCV valve/solenoid.
^ EGR SYSTEM:
Valve not opening, or open all of the time.
Refer to Powertrain Management/Emission Control Systems/Testing and Inspection/Procedures.





IGNITION CHECK: ^ Ignition 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.