Causes and Fixes P0451 Code: Evaporative Emission System Pressure Sensor / Switch Range Performance

How to fix P0451 Code: Evaporative Emission System Pressure Sensor / Switch Range / Performance

The EVAP system sends fuel vapors from the gas tank to the engine to be brunt away so they don't escape into the atmosphere.
A P0451 code is set when the computer (ECM/PCM) detects that the signal voltage from the fuel tank pressure (FTP) sensor, sometimes called EVAP Pressure Sensor, is not within the manufacturer-specified range.
The EVAP Pressure Sensor can be located on the fuel tank, on top of the fuel pump, or on the charcoal canister.
While Evap systems are similar, they can be designed differently, so it is best to get a diagram for the year, make, and model of the vehicle.

Possible Causes of a P0451 Code:
Pressure Sensor
Wiring Issue
EVAP Pressure is High (Bad Gas Cap, Vent Valve, Purge Valve, Charcoal Canister)

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