P0496 purge flow code — What the code means and how to fix it

A P0496 purge flow code means a problem was found in the evaporative emissions system

A P0496 purge flow code is s generic powertrain code related to the evaporative emissions system. The official description is  EVAP Flow During a Non-Purge Condition. This means the engine computer has detected air or fuel entering the engine from the purge valve when the computer is not commanding a purge event.

What are the possible causes a P0496 code?

• A faulty solenoid purge valve is the most common cause- The purge valve may be stuck open or shorted, causing excessive vapor flow. Replace the faulty purge valve.
• Leak in evaporative emissions system between the purge valve and the intake manifold
• Open or short in wiring to the solenoid purge valve- Check for damaged wiring or loose connections leading to the purge valve, purge flow sensor, or ECU. Repair wiring as needed.

How to diagnose a P0496 code

A purge valve is just an electrically controlled solenoid valve that allows the engine to suck fuel vapor from the charcoal canister to purge it.

1) Disconnect the purge valve. Inspect the valve for signs of charcoal particles. If you find them, the charcoal canister is damaged and must be replaced. The lines must be flushed and a new purge valve installed
2) Using a handheld vacuum pump and jumper wires, apply a vacuum to the purge valve and see if it hold the vacuum when the valve is closed. If not, replace the valve.
3) Apply power and ground to see if the valve opens and closes. Check for vacuum hold again. If it doesn’t hold vacuum when closed, replace it. If the valve doesn’t open or close when you apply or remove power and ground, replace the valve.
4) Check for leaks in the line from the purge valve to the intake manifold

©, 2022 Rick Muscoplat