4.6L, 5.4L F-150 EVAP Purge Valve Replacement

How to Replace the EVAP Purge Valve on a 1997 to 2003 Ford F-150

Modern engines feature an evaporative emissions control system, the purpose of which is to trap and dispose of fuel vapor rather than allow it to be expelled into the atmosphere. The system uses a charcoal canister to store fuel vapor. While the vehicle is operating, the PCM opens the EVAP purge valve, which then uses engine vacuum to draw fuel vapor out from the canister and into the engine, where it combusts. OBD II trouble codes related to emissions systems are often due, at least in part, to leaks in the EVAP system. However, another occurrence may be the malfunction of the EVAP purge valve itself. The purge valve is designed to remain in the closed position (no flow between the engine and charcoal canister) while the engine is starting. If it does not, the engine may hesitate, start rough, or become difficult to start due to a rich condition.

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EVAP purge valve location

• Disconnect the negative battery cable.

• The EVAP purge valve is located on the driver side firewall to the left of the brake booster and master cylinder.

• Disconnect the electrical connector from the right of the valve and the small vacuum line from the bottom.

EVAP purge valve hoses

• Next, remove the EVAP purge lines. The white and green quick connect fittings are removed by pushing in the tabs with two fingers while pulling downwards. Some finesse and side-to-side movement may be required to wiggle the fittings loose, as you do not want to break the fragile tabs.

EVAP purge valve electrical connector

• With the EVAP lines, vacuum line, and electrical connector disconnected, the EVAP valve can be removed and replaced - the two screws are removed with an 8 mm socket. Installation of the new EVAP purge valve is reverse.