Sierra 1500 4WD V8-5.3L VIN Z Flex Fuel (2005)
10. Remove the left exhaust manifold pipe nuts.
11. Remove the right exhaust manifold pipe nuts.
12. Remove the exhaust muffler nuts.
13. Remove the catalytic converter.
14. If necessary, remove the oxygen sensors.
Installation Procedure
Notice: Refer to Fastener Notice in Service Precautions.