EVAP Purge Solenoid
WARNING: This page is about a different car, the 2003 GMC Sierra and 2003 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.
The EVAP purge solenoid controls the flow of vapors from the EVAP system to the intake manifold. EVAP purge solenoid is located on top of intake manifold. See Figure . This normally closed solenoid is Pulse Width Modulated (PWM) by the control module to precisely control the flow of fuel vapor to engine. The solenoid will also be opened during some portions of EVAP testing, allowing engine vacuum to enter the EVAP system.