{"nhtsa_id":41063,"type":"service_bulletin","type_name":"Service bulletin","date_added":"1995-11-01","date":"1995-04-01","document_id":"RCL/91C50","mfr_campaign":null,"replaces":null,"component":"ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:EMISSION CONTROL","mfr_system":null,"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","document":null,"url":"https://open.wenmarpro.com/bulletins/41063","components":[{"id":"engine","name":"Engine","parent":null},{"id":"exhaust-emissions","name":"Exhaust and emissions","parent":null}],"codes":[],"topics":[],"vehicles":[{"make":"CHEVROLET","model":"ASTRO","year_from":1991,"year_to":1991,"match":null,"vehicle_ids":[]},{"make":"CHEVROLET","model":"C SERIES(LIGHT)","year_from":1991,"year_to":1991,"match":null,"vehicle_ids":[]},{"make":"CHEVROLET","model":"G SERIES","year_from":1991,"year_to":1991,"match":"exact","vehicle_ids":["1991_chevrolet_g-series"]}],"as_of":"2026-10-19","note":"A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.","attribution":[]}