Chevrolet Astro 1991 — technical service bulletin
Bulletin RCL/91C50 · NHTSA communication 41063 · issued Apr 1, 1995
Technical service bulletin
communication type
Engine and Engine Cooling
component
1991
model years
3
vehicle entries
Official summary
Recall 91-c-50 - general motors has determined that certain 1991 chevrtolet c/k trucks, m/l and g vans equipped with 4.3l engines [rpo lb4 or rpo lu2 (m van only)] may be emitting non-methane hydrocarbons (nmhc) in excess of california emissions standards. California emissions standards were established to protect the public health and wealfare 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 oxygen sensor. *tw
What a TSB means. Technical service bulletins are repair guidance manufacturers send to dealers — they are not recalls, and repairs are not automatically free (warranty extensions are an exception worth checking). The full document is available via NHTSA’s vehicle lookup.