Trouble codes › P0451
P0451 Evaporative Emission System Pressure Sensor/Switch "A" Range/Performance
EVAP
P0451 means the fuel tank pressure sensor's reading doesn't make sense for the conditions.
The fuel tank pressure sensor's reading doesn't make sense for the conditions, so the engine computer can't trust its EVAP leak tests.
Safe to drive. It affects emissions testing.
Common causes
- A failing fuel tank pressure sensor
- Wiring or connector problems
- A blocked or kinked EVAP hose affecting the reading
- An overfilled tank (topping off after the pump clicks)
Symptoms
- Check-engine light
- Usually nothing else
What to check first
- Avoid topping off the tank after the pump clicks off.
- With the gas cap off, the tank pressure reading should be close to zero.
- Inspect the sensor's connector and wiring.
- Replace the sensor if the reading is off with the cap removed.
What does P0451 mean on your vehicle?
The likely cause depends on your engine. iRepair researches your exact year, make, model and engine (service bulletins, recalls and owner reports) and tells you what to check first. Your first 3 questions are free.
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Related codes
General guidance for P0451 on most vehicles. Some makers use the same code a little differently; confirm in the service information for your vehicle, put safety first, and see a professional when in doubt.