P0466 low

EVAP Purge Flow Sensor Circuit Range/Performance

The P0466 code means the vehicle's onboard diagnostic system has detected: EVAP Purge Flow Sensor Circuit Range/Performance. This is a low severity code.

My Garage →

Keep driving?: Yes, but fix soon
DIY difficulty: moderate
Estimated cost: $80 - $350 (parts and labor)

Try This First ($8 Fix)

Stant 10838 OE Fuel Cap

A cracked or loose gas cap causes 60%+ of EVAP codes. This $8 replacement clears P0442, P0455, and P0457 more often than any other repair.

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Find the Leak

THIKPO Automotive Smoke Machine

If a new gas cap does not clear it, the leak is somewhere in the EVAP plumbing. A smoke machine finds the exact leak -- a cracked hose, bad seal, or stuck vent valve -- in minutes instead of guessing at parts.

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Clear the Code

ANCEL AD310 OBD-II Scanner

Clear the code after the repair. If the light stays off after 50 miles, you just saved $200+ in shop fees.

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Common Symptoms

Check Engine Light on
No driveability symptoms
EVAP monitor incomplete
Possible fuel vapor odor

Probable Causes (Ranked by Likelihood)

Degraded purge flow sensor Very High
Restriction in EVAP purge line High
Faulty purge valve not opening fully Moderate
EVAP canister saturated with fuel Low

Step-by-Step Diagnostic Procedure

Command EVAP purge valve open with scan tool while monitoring purge flow sensor. Reading should increase.
Check EVAP purge lines for kinks, blockages, or disconnections.
Test purge valve operation. It should click and allow airflow when commanded open.
Inspect EVAP canister for fuel saturation (liquid fuel in canister).

Frequently Asked Questions

What does range/performance mean for the purge flow sensor?

The sensor responds but its readings are outside the expected range during EVAP purge testing. The system detects flow but not the expected amount.

Can a saturated EVAP canister cause P0466?

Yes, if the canister is saturated with liquid fuel (from overfilling the tank or a failed purge valve), purge flow will be abnormal.

How do I check the EVAP purge valve?

Apply 12V to the purge valve and listen for a click. With power applied, you should be able to blow through the valve. With no power, it should be sealed.