Exhaust Leakage

WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.

Exhaust Leakage

Problem	Action
WARNING: While engine is operating, the exhaust system will become extremely hot. To prevent burns avoid contacting a hot exhaust system. DEFINITION: An exhaust leak may show stains at the area of the leak. The leak may be felt by holding a hand close to the suspected areas or using a smoke pencil. The leak may make a popping or hissing noise.Refer to Symptoms - Engine Exhaust prior to beginning this table.
Misaligned or improperly installed exhaust system components.	Align and tighten the components to the specifications. Refer to Fastener Tightening Specifications . Ensure the exhaust hangers are in the proper locations and not loose.
Exhaust leaks at the following connections: Exhaust manifold to pipe Flanges Pipe clamps	Tighten the components to the specifications. Refer to Fastener Tightening Specifications .
Seals or gaskets leaking. Exhaust manifold to cylinder head Exhaust pipes to exhaust manifold Catalytic converter connection EGR connections, if equipped	Replace the leaking seal or gasket. Refer to the affected components procedure for service.
Irregularities at the mating surfaces on the flange connections.	Repair as required or replace the affected component. Refer to the affected components procedure for service.
Exhaust manifold cracked or broken.	Replace the exhaust manifold. Refer to: Exhaust Manifold Replacement - Left Side Exhaust Manifold Replacement - Right Side .
Exhaust system component connection welds leaking.	Replace the leaking component. Refer to the affected component's procedure for service.
Muffler damaged or leaking at the seams.	Replace the affected muffler. Refer to Exhaust Muffler Replacement (LC9, LMG, LZ1, L20) , Exhaust Muffler Replacement (L96) , Exhaust Muffler Replacement (L94 with MWN) .