CTS V6-3.2L VIN N (2003)
12. Remove the bolt (1) securing the throttle body heater inlet hose/pipe to the intake plenum (2).
13. Disconnect the vacuum brake booster hose (3) from the vacuum source.
14. Remove the 2 bolts securing the engine control module (ECM) bracket to the intake plenum.
Intake Plenum
15. Remove the intake plenum bolt caps.
16. Remove the intake plenum bolts.
17. Lift the intake plenum from the intake manifold.
18. Remove the intake plenum O-ring seals.
19. Mask off the open ports to the intake manifold, in order to prevent foreign objects from entering the engine.
20. Disassemble the intake plenum if necessary.
21. Clean and inspect the intake plenum.
