Recall - Oxygen Sensor Replacement: Overview
No.: 90-C-50Group: 6F Engine Exhaust
February, 1995
SUBJECT:
OXYGEN SENSOR REPLACEMENT (CALIFORNIA VEHICLES ONLY)
MODELS:
1991 C/K TRUCKS, M/L AND G VANS WITH 4.3L ENGINES AND CALIFORNIA EMISSIONS RPO NB2
General Motors has determined that CERTAIN 1991 C/K Trucks, M/L and G Vans with 4.3L engines (RPO LB4 - VIN Code "Z") and M Vans equipped with 4.3L (RPO LU2 VIN Code "B") may be emitting non-methane hydrocarbons (NMHC) in excess of California emission standards. California emission standards were established to protect the public health and welfare from dangers of air pollution. Excess emission of NMHC may cause a vehicle to fail state mandated emission tests.
To correct this condition, dealers are to install a new exhaust oxygen sensor.