NHTSA service bulletin

NHTSA Service Bulletin 41063: 1991 Chevrolet Astro

Official manufacturer communication context for 1991 Chevrolet Astro, with affected products, buyer checks and links into Carchieve recall, problem and VIN research.

NHTSA service bulletin 41063 summary graphic for 1991 Chevrolet Astro
41063NHTSA document ID
Emissions communicationcommunication type
3affected product rows
90/100quality score

Reviewed June 2026 from NHTSA manufacturer communication and service bulletin records. Carchieve is independent and not affiliated with any vehicle manufacturer or government agency.

Quick answer

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 this bulletin may mean before buying

Treat this as service research, not a verdict on one car. Before you buy, compare this communication with official recall campaigns, model-level owner complaint patterns, and the exact vehicle’s VIN-decoded specifications. A bulletin can help you ask a seller or dealer sharper questions about software updates, known repairs, warranty extensions and service history.

Affected products listed in this communication

MakeModelModel yearsBuyer note
ChevroletAstro1991Ask for service records and run the exact VIN before purchase.
ChevroletC Series(light)1991Ask for service records and run the exact VIN before purchase.
ChevroletG Series1991Ask for service records and run the exact VIN before purchase.

Buyer checklist

  1. Run the 17-character VIN and confirm the year, make, model, engine and equipment match the listing.
  2. Check recall campaign pages for safety actions that may require dealer repair.
  3. Compare this bulletin with common problem pages for the same model and component area.
  4. Ask the seller or dealer whether the bulletin procedure, update or inspection has already been completed.
  5. Use the used-car buying checklist and get an independent inspection.

Frequently asked questions

What is NHTSA service bulletin 41063?

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.

Is a service bulletin the same as a recall?

No. A recall is a safety campaign with a required remedy for affected VINs. A service bulletin or manufacturer communication usually describes diagnostic, repair, software, warranty or service information.

How should a used-car buyer use this bulletin?

Use it as a research signal. Compare it with recalls, owner complaints, service records, a VIN report and an independent inspection before buying.

Check the exact VIN before you buy

Model-level pages show public safety patterns. A full VIN report helps confirm the exact vehicle, decoded specs, recall applicability and buyer checks.

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