P0466: EVAP Purge Flow Sensor Circuit Range/Performance

What P0466 means

P means powertrain (engine and transmission). The 0 marks a generic code defined by SAE, so the same number means the same thing across makes. The third character, 4, places it in the auxiliary emission controls subsystem; the last two digits identify the specific fault.

Some vehicles use a purge flow sensor to confirm vapour is actually moving from the canister to the engine when the purge valve opens.

What “Range/Performance” means here

"Range/Performance" means the circuit is electrically intact — the signal sits inside its normal window — but the value does not make sense for the operating conditions. The module cross-checks it against what other inputs predict (a rationality test). That usually points at the EVAP purge flow sensor itself or the system it measures, rather than at the wiring.

What you may notice

Symptoms depend on the vehicle and on how the module responds to the fault. Any of these can accompany P0466:

• Usually none
• Purge flow codes stored alongside

Where to start diagnosing P0466

1. Check the sensor connector and wiring.
2. Confirm the purge valve operates.
3. Check for blocked purge lines.

Clear the code only after recording freeze frame data: it shows the engine speed, load and temperature at the moment the fault set, which is often the best clue to reproducing it.

Live data to watch

These standard OBD2 values relate to P0466. Support varies by vehicle; a value your car does not report will simply be missing.

Related codes

Codes from the same EVAP purge flow sensor family. If several are stored together, the shared part — wiring, a common reference voltage, or the component itself — is the place to start.

Further reading

• The light came on right after you filled up
• OBD2 readiness monitors explained

Frequently Asked Questions