Powertrain, generic · Auxiliary emission controls

P0497 EVAP System Low Purge Flow

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

The evaporative emission (EVAP) system stores fuel vapour from the tank in a charcoal canister; a purge valve lets the engine draw it off, and a vent valve opens the canister to fresh air. P0497 is the counterpart of P0496: the module purges but sees too little or no purge flow, judged indirectly from fuel trim, idle control or tank vacuum – CARB requires missing purge flow to be detected. Code-specific use is documented only by Land Rover (5.0-litre V8) and in a GM fault group for systems with a sealed tank (Volt, ELR); standard GM and Ford systems use other codes, such as P0455. The canister is then not purged and saturates.

Likely causes

Purge valve stuck closed, does not open
Purge line off, kinked or blocked (check valve sticking)
Canister or vent filter blocked (e.g. after overfilling)
Vent valve stuck closed

Symptoms

  • Check engine light on
  • Fuel smell around the car
  • Fuel nozzle clicks off early

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–450
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

evap purge valvepurge linecharcoal canisterengine control module

Related codes

P0496P0441P0443P0455P04AF

References: law.cornell.edu, static.nhtsa.gov, gsi.ext.gm.com.