K 2500 Truck 4WD V6-262 4.3L (1988)
Catalytic Converter: All Technical Service Bulletins
Engine - Rough Idle and/or Converter Odor
Number:
88-424-6E
Section:
6E
Date:
July, 1989
Subject:
ROUGH IDLE AND/OR CONVERTER ODOR
Model and Year:
1988 C1, C2, K1, K2 TRUCKS WITH 4.3L (VIN CODE Z) ENGINE
TO:
ALL CHEVROLET DEALERS
Some 1988 C/K-trucks equipped with 4.3L (VIN Code Z) engines may exhibit an exhaust odor often described as sulfur or rotten egg smell at idle
following sustained highway driving or trailer towing. Additionally, some trucks may exhibit rough or unstable idle quality.
These conditions may generally be addressed by relocation the oxygen sensor from the left hand exhaust manifold to the exhaust takedown (Y-pipe) and
installing the appropriate calibration PROM.
PARTS REQUIRED:
To accomplish this, it will be necessary to obtain the parts listed below:
Quantity
Description
Part Number
1
Exhaust Y-pipe
15620225
1
Plug
10017198
2
Seal
15522434
1
Calibration PROM
See Application Table
Parts are currently available from GMSPO.
SERVICE PROCEDURE:
1)
Disconnect the battery.
2)
Remove the exhaust Y-pipe and discard.
3)
Install new Y-pipe (P/N 15620225). It may be necessary to replace the exhaust manifold to Y-pipe seals (P/N 15522434) prior to installing the
new Y-pipe.