East Coast Supercharging ECS Stage 2 2003+ Fuel System - Manual (Page 15)

Reinstall EVAP pipe.
Connect the EVAP crossover pipe (2) quick connect fitting at the left fuel tank.
Lubricate the crossover tube to fuel tank connection O-rings (1-4) with GM P/N 1051717
rubber lubricant.
Important: Note the location of the T-shaped alignment feature (5) between the jet
pump feed/return pipes connector.