Excessive Exhaust Emissions (Odors)

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

PRELIMINARY CHECKS
- Refer to Preliminary Checks. - Important Preliminary Checks
- Perform Diagnostic System Check. Testing and Inspection
- Make sure engine is at normal operating temperature.
- If EMISSION TEST shows excessive CO and HC check items which cause vehicle to run RICH. Long term fuel trim memory less than 115 refer to Diagnostic Aids in Diagnostic Charts / DTC 45 Rich Exhaust. Testing and Inspection
- If EMISSION TEST shows excessive Oxides of Nitrogen(NOx) check items which cause engine to operate LEAN or too hot.

SENSORS
If the scan tool indicates a very high coolant temperature and the system is running lean, check the cooling system and cooling fan for proper operation.

FUEL SYSTEM
If the system is running rich, (long term fuel trim less than 115), refer to Diagnostic Aids in Diagnostic Charts / DTC 45 Rich Exhaust. Testing and Inspection

If the system is running lean, (long term fuel trim greater than 150),refer to: Diagnostic Aids in Diagnostic Charts / DTC 44 Lean Exhaust. Testing and Inspection

CHECK:

- For properly installed fuel cap.
- Fuel pressure. Refer to Diagnostic Charts / Chart A-6 Fuel System Diagnosis. Testing and Inspection
- If test shows excessive NOx, check items which cause engine to operate LEAN or too hot.
- EVAP Canister for fuel loading.

ADDITIONAL CHECKS
CHECK:

- For vacuum leaks.
- For lead contamination of catalytic converter (look for the removal of fuel filler neck restrictor).
- Carbon build-up. Remove carbon with top engine cleaner. Follow instructions on can.
- EGR valve for not opening.
- Crankcase ventilation valve for being plugged, stuck, or blocked Positive Crankcase Ventilation (PCV) hose.