K 1500 Truck 4WD V6-262 4.3L (1986)
PROM - Programmable Read Only Memory: Customer Interest
Engine - Rich Exhaust Odor Complaints
Number:
86-149
Section:
6E
Date:
SEPT., 1986
Subject:
EXHAUST ODOR COMPLAINTS
Model and Year:
1986 "M" VAN WITH 4.3L TBI ENGINE (VIN CODE Z) AND AUTOMATIC TRANSMISSION
TO:
ALL CHEVROLET DEALERS
Customer comments may be received regarding a rich exhaust odor on 1986 "M" Vans with 4.3L throttle body injection (TBI) engines. This condition
can be improved by installing a revised calibration prom as listed below.
SERVICE PROM
EMISSION SYSTEM
TRANSMISSION
16068877
Federal
Automatic
16068926
California
Automatic
Use applicable labor operation:
NOTICE:
This prom will also reduce cold engine fast idle speeds from approximately 850 RPM to 750 RPM in drive.
Slight odor may still be present during warm-up, severe throttle maneuvers, or after wide open throttle applications. This is
characteristic of systems equipped with three way catalytic converters. The vehicle should also be inspected to ensure no intake
manifold or exhaust manifold leaks are present.
