Excessive Exhaust Emissions (Odors)

DEFINITION: Vehicle fails an emission test or vehicle has excessive "rotten-egg" smell. (Excessive odors DO NOT necessarily indicate excessive emissions).

Perform careful visual check.
Perform "DIAGNOSTIC CIRCUIT CHECK."

CHECK:

- EGR valve not opening.
- Vacuum leaks
- Faulty coolant system and/or coolant fan operation.
- Remove carbon with top engine cleaner. Follow instructions on can.

- If emission test indicates excessive NOx, check for items which cause car to run lean or too hot.
- If emission test indicates excessive NOx, and CO or exhaust has excessive odors, check for items which cause car to run RICH.
- Incorrect fuel pressure. Use CHART A-7 in A-CHARTS.
- Fuel loading of evaporative vapor canister.
- PCV valve plugging, sticking, or blocked PCV hose. Check for fuel in crankcase.
- Catalytic converter lead contamination (Look for removal of fuel Filler neck restrictor.)
- Improper fuel cap installation
- Faulty spark plugs, plug wires, or ignition components.