

DIESEL SMOG CHECK PROGRAM
THE DIESEL SMOG APPLIES TO ALL 1998 AND NEWER DIESEL POWERED VEHICLES UNDER 14,000 GVWR
DIESEL INSPECTION PROCEDURE:
- VISUAL TEST
- OBD II TEST
- VISIBLE SMOKE TEST
VISUAL CHECK LIST:
- POSITIVE CRANKCASE VENTILATION “PCV” OR CRANKCASE DEPRESSION REGULATOR “CDR”
- DIESEL OXIDATION CATALYST “DOC”
- DIESEL PARTICULATE FILTER “DPF”
- NOX ABSORBER
- EGR
- FUEL INJECTION
- TEMPERATURE AND PRESSURE SENSOR
- WIRING SENSOR/SWITCHES/COMPUTERS
- VACUUM LINE CONNECTIONS TO SENSORS/SWITHES
- OTHER DIESEL EMISSION-RELATED COMPONENTS
- TURBO/SUPERCHARGER, EXHAUST/INTAKE, ETC.
OBD II CHECK:
- CHECK ENGINE LIGHT “MIL” IS OPERATIONAL
- MIL ON/OFF
- OBD READINESS STATUS CODES
VISIBLE SMOKE TEST CONSISTS OF:
- IDLE TEST
- IDLE CRANKCASE “CDR/PCV” TEST
- SNAP TEST