EXPANDED CATALYTIC CONVERTER PROM WITH LEANER DUTY CYCLE

ANYTIME AN EXPANDED CONVERTER IS REPLACED, IT IS NECESSARY TO INSPECT THE ECM TO INSURE THAT THE LEANER DUTY CYCLE PROM IS INSTALLED. NEW PROMS ENTERED PRODUCTION APPROXIMATELY MAY 25, 1981. THESE NEW PROMS HAVE A LEANER OPEN LOOP DUTY CYCLE. (REFERENCE CHEVY#81-T-19,81-T-55) THE CORRECT PROMS CAN BE IDENTIFIED BY THE BROADCAST CODES LISTED BELOW AND LOCATED ON THE BACK SIDE OF THE PROM (REFER TO FIGURE 1).

3.8L 229 CU. IN. V6 VEHICLE TYPE SERVICE PROM BROADCAST PART NO. CODE A-COUPE, SEDAN, A-SPECIAL 1225364 ABP A-WAGON, EL CAMINO, F-CAR 1225363 ABS B-CAR 1225362 ABR ALL MANUALS 1225360 ABT

4.4L 267 CU. IN. V8 VEHICLE TYPE SERVICE PROM BROADCAST PART NO. CODE A-COUPE, SEDAN, A-SPECIAL 1225318 ABV B-WAGON 1225319 ABW A-WAGON, EL CAMINO 1225320 ABX F-COUPE 1225321 ABY B-COUPE, SEDAN 1225322 ACK

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.