Excessive Exhaust Emissions (Odors)

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

INSPECT
IF TEST SHOWS EXCESSIVE CO AND HC (or also has excessive odors),
check items which cause car to run RICH.

Check
^ Make sure engine is at normal operating temperature.
^ Fuel pressure. See Chart A-7. Chart A-7 Fuel System Diagnosis


^ Positive Crankcase Ventilation ([1][2]PCV) valve for being plugged, stuck, or blocked PCV hose, or fuel in the crankcase.

^ Canister for fuel loading. See Chart C-3. Chart C-3 Canister Purge Check


^ Spark plugs, plug wires, and ignition components. See Ignition System.

^ Injector balance. See Chart C-2A. Chart C-2A Injector Balance Test

^ Check for lead contamination of catalytic converter (look for removal of fuel filler neck restrictor).
^ Check for properly installed fuel cap.

If The System is Running Rich, (block learn less than 110)
Refer to the "Diagnostic Aids" section in "Diagnostic Trouble Code 45".


If Test Shows Excessive NOx
^ Check items which cause car to run LEAN, or to run too hot.
^ EGR valve for not opening. See Chart C-7A.

^ Vacuum leaks.
^ Coolant system and coolant fan for proper operation. See Chart C-12A.

^ Remove carbon with top engine cleaner. Follow instructions on can.

If The System is Running Lean, (block learn greater than 150)
Refer to the "Diagnostic Aids" section in Diagnostic Trouble Code 44.