GM Service Manual Online
For 1990-2009 cars only
Figure 1:

EVAP System Overview


Object Number: 678941  Size: LF
(1)EVAP Canister Purge Solenoid
(2)EVAP Canister
(3)Fuel Fill Neck/Fill Cap
(4)Rollover Valve/Fuel Tank Pressure (FTP) Sensor
(5)Fuel Tank
(6)EVAP Canister Vent Solenoid
(7)Vent Hose/Pipe
(8)EVAP Vapor Pipe
(9)EVAP Purge Pipe
(10)EVAP Service Port
Figure 2:

EVAP Hose/Pipe Routing W/Dual Tanks and One Fill Neck


Object Number: 678911  Size: LF
(1)EVAP Canister Purge Valve
(2)EVAP Canister
(3)EVAP Vapor Pipe
(4)Front Fuel Tank
(5)Fuel Fill Neck
(6)Rear Fuel Tank
(7)EVAP Canister Vent Valve
(8)Vent Hose/Pipe
(9)EVAP Purge Pipe
(10)EVAP Service Port