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

The EVAP Pressure Sensor, also known as a Fuel Tank Pressure (FTP) Sensor is a device that measures air pressure or vacuum in the evaporative emission (EVAP) system. This sensor is typically found on top of or inside of the fuel tank.

Code P0451 is triggered when the FTP sensor signal falls outside the specified range for an extended period.

NOTE: An understanding of EVAP systems could help you address code P0451 better. Here’s a primer.

What Does the P0451 Code Mean?

The P0451 code is defined as Evaporative Emission Control System Pressure Sensor/Switch Range/Performance.

This diagnostic trouble code is set by the PCM when it detects that the Evaporative Pressure Sensor (also known as a Fuel Tank Pressure Sensor) indicates pressure change values that are not within the manufacturer-specified range. This could happen while an EVAP monitor test is being conducted and/or during the operation of a vehicle.

This code belongs to a range of related evaporative emission trouble codes which include P0450, P0452, P0453, P0454, P0455, P0456, P0457, P0458, and P0459.

What are the possible causes of the P0451 code?

Defective EVAP pressure sensor (fuel tank pressure sensor)

The P0451 code is considered one of the more straightforward trouble codes. This error code is typically set due to a faulty or failing EVAP/Fuel Tank Pressure Sensor.

Damaged wiring or poor connections in the EVAP/Fuel Tank Pressure Sensor circuit

Issues with the EVAP/Fuel Tank Pressure Sensor’s circuit can also trigger code P0451.

PCM failure

In rare cases, this trouble code may be erroneously set by a malfunctioning PCM in need of a software update.

Symptoms of the P0451 code

Check Engine Light will illuminate

In most cases, there are no observable or adverse symptoms that accompany this trouble code, other than an illuminated check engine light.

How to Diagnose the P0451 Code

To resolve the P0451 code, you need to determine its exact cause, which can prove challenging. If you are not confident with your DIY automotive repair skills, it’s best to leave the task to your mechanic. However, if you’re confident about your automotive knowledge, you can try watching the video below to get an idea of what diagnosis might involve:

How to Fix the P051 Code

There’s no universal solution for code P051. The repair process will vary depending on the exact cause of the issue and the vehicle’s year, make, and model. It’s always best to bring your car to a mechanic if you’re unsure about diagnosis and repair.

If you think you have enough DIY experience to resolve the issue, it’s highly recommended that you still use online repair manuals to guide you through the repair process. You should also consider investing in an ALLDATA single-vehicle subscription, which should help you clear the P0451 code and give you more information on other repairs you may have to do on your car in the future.

Where to Get a New EVAP Sensor for Your Ride 

If your OBD scan tool reads a P0451 code, there’s a high possibility you’re dealing with a bad evaporative emission control (EVAP) sensor. Good thing it’s not that hard to find an EVAP sensor for your ride. 

You don’t have to leave the comforts of your home just to get your hands on a new EVAP sensor. All you have to do is go to CarParts.com, and browse through our selection of EVAP sensors. These aftermarket parts are made to function just like your factory sensors.

All our EVAP sensors come with a guaranteed fit, so you won’t have to worry about compatibility. Just make sure to input your ride’s exact details into our vehicle selector—including the model year.

Need your EVAP sensor as soon as possible? We’ve got you covered. Our distribution centers are located across the country, so you’ll only have to wait a few days for your orders.

Replace your EVAP sensor right away once you’ve confirmed it’s causing the issue. Check out our catalog now and enjoy the best deals!