Sierra 1500 4WD V8-6.0L (2007)
19. If the vehicle is a 2500/3500 series, remove the muffler to catalytic converter nuts.
20. Remove the HO2S.
21. Remove the catalytic converter to exhaust manifold nuts (1). (1500 series shown, 2500/3500 series similar).
22. Separate the catalytic converter assembly from the exhaust manifolds.
23. Remove the catalytic converter assembly from the exhaust muffler.
24. If replacing the catalytic converter assembly, perform the following steps, otherwise proceed to step 4 in the installation procedure.
25. Remove the exhaust seals (2 and 3).
