Purge Flow Sensor Circuit High Input
The purge flow sensor is sending a signal that's too high, meaning the ECU thinks too much fuel vapor is flowing through the charcoal canister. It's like a water meter reading that's stuck on maximum even when only a trickle is flowing.
The ECU monitors the purge flow sensor voltage output to verify the charcoal canister purge control valve is operating correctly. When vapor is purged into the engine, the sensor should produce a proportional voltage signal. A high input indicates excessive flow or a sensor malfunction.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| Sensor Voltage | 0.5–4.5 volts (proportional to flow) | >4.8 volts or stuck high |
| Flow Rate | 0–50 g/s typical | Exceeds expected maximum for engine load |
Code P1450 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P1450 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.