Yukon Denali AWD V8-6.2L (2007)
Catalytic Converter: Technical Service Bulletins
Exhaust System - Catalytic Converter Precautions
Bulletin No.: 06-06-01-010A
Date: February 04, 2008
INFORMATION
Subject:
Information on Close-Coupled Converter and Engine Breakdown or Non-Function Due to Severe Overheat or Lack of Oil Causing Piston(s) Connecting
Rod(s) Crankshaft Cylinder(s) and/or Head(s) Camshaft(s) Intake and/or Exhaust Valve(s) Main and/or Rod Bearing(s) Damage
Models:
2004-2008 GM Passenger Cars and Trucks
with Close-Coupled Catalytic Converters
Supercede:
This bulletin is being revised to add model years. Please discard Corporate Bulletin Number 06-06-01-010 (Section 06 - Engine/Propulsion System).
Certain 2004-2008 General Motors products may be equipped with a new style of catalytic converter technically known as the close-coupled catalytic
converter providing quick catalyst warm-up resulting in lower tail pipe emissions earlier in the vehicle operating cycle.
If an engine breakdown or non-function were to occur (such as broken intake/exhaust valve or piston) debris may be deposited in the converter through
engine exhaust ports. If the engine is non-functioning due to a severe overheat event damage to the ceramic "brick" internal to the catalytic converter
may occur. This may result in ceramic debris being drawn into the engine through the cylinder head exhaust ports.
If a replacement engine is installed in either of these instances the replacement engine may fail due to the debris being introduced into the combustion
chambers when started.
When replacing an engine for a breakdown or non-function an inspection of the catalytic converters and ALL transferred components (such as exhaust/
intake manifolds) should be performed. Any debris found should be removed. In cases of engine failure due to severe overheat dealers should also
inspect each catalytic converter for signs of melting or cracking of the ceramic "brick". If damage is observed the converter should be replaced.
Disclaimer
