Exhaust System - Noises During Deceleration
BULLETIN NO.: 99-T-41AGROUP/SEQ. NO.: Engine - 10
ISSUE DATE: March, 2000
CORPORATION NO.: 99-06-05-004A
SUBJECT:
Exhaust System Noises During Deceleration on SOHC Engines with Manual Transaxles (Install a DOHC Service Replacement Intermediate Exhaust Pipe with Resonator)
Due to the addition of model years and a condition 2, this bulletin has been revised and supercedes bulletin 99-T-41, which should be discarded.
MODELS AFFECTED:
Condition 1:1998 - 2000 Saturn S-Series vehicles built after and including VIN WZ216016 equipped with base SOHC engines and manual transaxles (RPOs L24 and MP2)
Condition 2:
2000 Saturn S-Series vehicles equipped with base SOHC engines, manual transaxles, and federal emissions (RPOs L24, MP2, and NF2).
CONDITION:
Condition 1:
Some customers may comment about an exhaust system "pop" type noise during an extended deceleration between 2500-2200 rpm in 3rd gear or 3500-3200 rpm in 2nd gear.
Condition 2:
Some customers may comment about an exhaust system raspy" type noise during closed throttle deceleration in any gear between 3600-3200 rpm.
CAUSE:
Condition 1:
This condition is caused by fuel delivery during extended deceleration periods. On an extended deceleration with no throttle input, the powertrain control module (PCM) turns Off fuel to lean out the air/fuel mixture within a specified rpm range. A "pop" noise is heard when fuel is added back into the air/fuel mixture.
Condition 2:
This condition is caused because a smaller catalytic converter was used on 2000 model year S-Series vehicles. This smaller catalytic converter does not absorb exhaust system sounds as well as previous models. A vehicle equipped with a combination of an SOHC engine, manual transaxie, and federal emissions is more sensitive to this noise condition.
CORRECTION:
Both conditions can be corrected by installing a DOHC intermediate exhaust pipe (P/N 21013306).
PARTS REQUIREMENTS:
21013306 Pipe Asm - Exh
CLAIM INFORMATION:
To receive credit for this repair during the warranty coverage period, submit a claim through the Saturn Dealer System using the appropriate Electronic Labor Time Guide and Labor Operation Code L2420 (Pipe, Intermediate Exhaust - Replace).