When Should You Replace Your Fuel Tank Pressure Sensor?

A fuel tank pressure sensor is an important component of a vehicle's fuel system. It monitors the pressure in the fuel tank to detect leaks and faulty gas caps, which can cause fuel vapours to escape into the atmosphere. A faulty sensor can cause a range of issues, including a check engine light, poor fuel economy, reduced engine performance, and difficulty starting the engine.

If you suspect your fuel tank pressure sensor is faulty, it is best to have it diagnosed and replaced by a professional technician to avoid the risk of fire and the potential difficulty of diagnosis. The cost of replacement typically ranges from $150 to $350, including parts and labour.

So, while it is not advisable to drive with a faulty sensor for extended periods, it is possible to continue driving and replace the sensor at a more convenient time.

Faulty gas caps

A faulty gas cap will not cause major performance issues with your vehicle, but it can set off the Check Engine Light, which will prevent your vehicle from passing an emissions test. Here are some common symptoms of a faulty gas cap:

• Cap does not tighten properly: One of the most common symptoms of a faulty gas cap is that it does not tighten properly. Most gas caps are designed to click once they are tightened sufficiently. If the cap does not click, or clicks and then pops loose, it may need to be replaced.
• Fuel smell from the vehicle: If the gas cap seal becomes damaged or worn, it may cause fuel vapors to leak from the filler neck, resulting in a gasoline odor from the vehicle.
• Check Engine Light comes on: An illuminated Check Engine Light can be caused by a faulty gas cap, as it is part of the vehicle's evaporative emissions system. An improperly sealing fuel cap may cause an evap system leak, which will set off the Check Engine Light when the computer detects the leak.
• Water in the fuel tank: A bad gas cap can allow water to get into the fuel tank, which can contaminate the fuel and cause performance issues.
• Poor fuel economy: A faulty gas cap can lead to poor fuel economy if the fuel is allowed to escape as vapour or if it becomes contaminated.

Illuminated check engine light

An illuminated check engine light is one of the most common symptoms of a faulty fuel tank pressure (FTP) sensor. While the light alone does not necessarily indicate a problem with the FTP sensor, it is one of the most noticeable signs. When the check engine light comes on, it is recommended to get your car checked by a mechanic.

The FTP sensor is part of the evaporative emissions (EVAP) system and plays a crucial role in maintaining optimal vehicle performance. It monitors pressure to detect evaporative leaks and loose or faulty gas caps that may prevent fuel vapours from being contained in the EVAP system. When the FTP sensor detects a problem, it transmits data to the engine computer, which then triggers the check engine light.

In addition to the illuminated check engine light, other symptoms of a faulty FTP sensor include engine stalling, loss of power, and hard starts. These issues may be due to incorrect signals sent by the sensor, resulting in an incorrect fuel-to-air ratio and a lean fuel mixture.

To diagnose a faulty FTP sensor, a mechanic can use an OBD2 scanner, which will provide a specific code related to the problem. For example, codes such as P0442, P0453, and P0455 indicate issues with the FTP sensor.

It is important to note that the FTP sensor is typically located inside or on top of the fuel tank, making it challenging for the average car owner to access and repair. Therefore, it is recommended to consult a professional technician to replace the FTP sensor if needed.

Ignition issues

A malfunctioning FTP sensor can also cause the engine to run improperly, leading to rough idling. This may manifest as noticeable vibrations or shaking in the vehicle cabin.

In addition, if the FTP sensor provides inaccurate information to the ECM (Engine Control Module), the engine may not receive the correct fuel/air mixture and ignition timing, leading to poor acceleration. While this issue can be subtle at first, it may become more noticeable over time.

Location of the fuel tank pressure sensor

The fuel tank pressure sensor is often located on top of, or inside, the fuel tank, on top of the fuel pump module.

For a 2015 Ford F-150, the sensor is located on top of the fuel tank. To access it, you would need to drop the tank.

For a Chevy Silverado 2500HD 8.1L, the sensor is on the fuel primary fuel pump assembly, and requires the tank to be removed.

The sensor is usually part of the fuel pump assembly, and can be accessed by dropping the fuel tank.

Cost of replacement

The cost of replacing a fuel tank pressure sensor varies depending on the type of car and the auto repair shop. The average price ranges from $256 to $304, with labor costs estimated between $139 and $176, and parts priced between $118 and $128.

For example, the cost of replacing a fuel pressure sensor for a 2006 Buick LaCrosse was $386.96 CDN ($350 USD). The sensor was inside the fuel tank, so the tank had to be drained and removed, which added to the labor cost.

The cost of the sensor part itself can range from $150 to $300, depending on the shop's labor rate. If the entire fuel rail needs to be replaced, the cost can range from $600 to $1300.

It is important to note that the average cost of replacement does not include taxes and fees and may vary depending on your location.

Frequently asked questions