Excessive Exhaust Emissions (Odors)

Definition: Car fails an emission test. May also have excessive "rotten egg" smell (hydrogen sulfide).

^ If test shows excessive CO and HC, (also has excessive odors):
^ Check items which cause car to run RICH.
^ Make sure engine is at normal operating temperature.
^ Check for high fuel pressure. Should be 40-50 psi (276 - 345 kPa) at key "ON", engine "OFF". If fuel pressure not in this range, see Chart A-4B. A-4B Dynamic Fuel Pressure Check
^ Check for incorrect idle speed.
^ Check for incorrect timing. See Vehicle Emission Control Information Label.
^ Check for fuel in engine crankcase. If found, check for improper PROM. (PROM I.D. parameter ED99)
^ Check for stuck PCV valve or blocked PCV hose.
^ Check for air to exhaust manifold ports at all times.
^ Check condition of spark plugs, plug wires, and distributor cap.
^ Check for lead contamination of catalytic converter (look for removal of fuel filler neck restrictor).
^ Check for plugged air cleaner element.

^ IF TEST SHOWS EXCESSIVE NOx:
^ Check items which cause car to run LEAN, or to run too hot.
^ Check EGR valve for not opening.
^ Check for vacuum leaks.
^ Check coolant system and coolant fan for proper operation.
^ Remove carbon with top engine cleaner. Follow instructions on can.
^ Check ignition timing for excessive base advance. See Emission Control Information label.