1991 Audi S4
Recalls, most-reported problems, crash-test ratings, fuel economy and what a 1991 Audi S4 is worth — from official NHTSA and EPA data. 3 on record.
1991 Audi S4 at a glance
Included: that car's specs and build sheet, model-year recall campaigns and a fair price.
1991 Audi S4 recalls 1
VEHICLE DESCRIPTION: PASSENGER VEHICLES. SOME AIR BAG SENSORS DO NOT COMPLY WITH AUDI'S DURABILITY STANDARDS OVER THE LIFETIME OF THE VEHICLE.
Fix: DEALERS WILL REPLACE THE AIR BAG SENSOR CONTROL MODULE.
Source: U.S. NHTSA, checked 4 Nov 2026. A campaign covers the model year; to see whether a particular car still needs the repair, check its VIN on NHTSA.gov or ask a franchised dealer.
Investigations & service bulletins
Manufacturer service bulletins 6
Technical notes the manufacturer sent to dealers about known issues and fixes. Useful to mention to a mechanic — they are not recalls and repairs may not be covered.
This special notice is to inform dealers to return all part numbers listed in the document and order the superseded part numbers going forward.
Bulletin SM 44-2017 EN · Equipment · Jun 2017Due to increasing requests for high voltage personal protective equipment (HVE PPE) for dealer technicians working with high voltage vehicles (Hybrid, Plugin Hybrid, Electric Vehicle), the Volkswagen Tools and Equipment Team has identified two US based supplie…
Bulletin ATE-17-05 · Equipment · Mar 2017AUDI: ENGINE, ON SOME VEHICLES, WOULD RUN IRREGULARLY OR HAVE MALFUNCTION INDICATOR LAMP (MIL) ON OR POSSIBLE FILTER ELEMENT FOR CAMSHAFT ADJUSTMENT VALVE CAN LOOSEN AND IN OIL CIRCUIT, THERE IS NO DAMAGE FROM LOOSENED PARTICLES. MODEL ALL. ALL YEARS. *PE
Bulletin SB-01-15-29 · Engine · Jul 2015Due to new Minnesota state regulations regarding biofuels, biodiesel blends of B5 or less may not be available in the State of Minnesota.
Bulletin AUD4927ENG · Jul 2014Google Maps Street View (NVLW))
Bulletin Update91i8 · May 2014HEADLIGHT AIMING, USING HELLA UNIVERSAL BEAMSETTER. *KB
Bulletin 20056243 · Exterior Lighting · Feb 2007Source: NHTSA Office of Defects Investigation, listed for the S4. Model-year data, not specific to one car.
About the Audi S4
The Audi S4 is the high performance variant of Audi's compact executive car A4. The original Audi S4, built from 1991 until 1994, was a performance-oriented version of Audi's 100 saloon/sedan. All subsequent S4s, beginning with the "B5" platform car in 1997, have been based on the Audi A4; and as the A4 has evolved from one generation to the next, so has the S4. Audi's platform generation names, beginning with "B5" in 1997, are used throughout to distinguish between generations/evolutions of these products.
From Wikipedia, licensed CC BY-SA 4.0. Describes the model line in general, not this model year specifically.