P0467

P0467 means the ECM sees the purge flow sensor signal pinned LOW — below the minimum expected voltage threshold (typically below 0.3-0.5V) for an extended period, regardless of commanded purge duty. Either the sensor is dead, the 5V reference is missing, the signal wire is shorted to ground, or the sensor is reading actual zero flow because no vapor is reaching it. Cheapest-first ladder: (1) Backprobe the purge flow sensor signal pin with KOEO — should sit at baseline 0.5-1.0V on most platforms; reading 0.0V flat means signal-to-ground short OR dead sensor. (2) Disconnect the sensor and check the 5V reference at the harness side — should read 4.9-5.1V; missing reference means ECM-side wiring fault or blown internal fuse. (3) Check ground continuity at the sensor harness; corroded grounds drag signal voltage to zero. (4) Swap-test with a known-good sensor before tearing into wiring — purge flow sensors on Volvo/Hyundai platforms commonly fail internally with the output transistor stuck low, mimicking a wiring fault. (5) Verify the purge solenoid is actually commanding open — a stuck-closed solenoid means zero flow reaches the sensor, which reads correctly as 0.5V baseline and the ECM blames the sensor. Before condemning the purge flow sensor, scope the purge solenoid driver waveform — if the solenoid never opens, the sensor is innocent and the solenoid (or its driver) is the actual fault ($85 solenoid vs. $350 sensor).

Vehicle-specific patterns: 2008-2014 Volvo S60/XC60/XC90 throws P0467 from connector pin fretting at the purge flow sensor where the harness clip releases tension over time and the pins back out of full contact; reseat and pack with dielectric grease. 2011-2016 Hyundai Sonata/Tucson GDI throws P0467 from a known-failure pattern where the sensor's internal hot-wire fails to baseline-zero — Hyundai TSB territory, check VIN coverage. 2012-2015 Kia Optima GDI shares the pattern. 2007-2013 Ford Edge/Flex 3.5L throws P0467 from purge line collapse upstream of the sensor (no vapor reaching the element). 2009-2014 Audi A4/A6 2.0T throws P0467 from sensor connector corrosion at the engine bay rear bulkhead. Estimated repair: $140 to $480.