What Happens When the Fuel Tank Pressure Sensor Goes Bad?(Symptoms)

Also known as the fuel rail sensor, the fuel tank pressure sensor is an integral part of the evaporative emissions control systems or rather EVAP.

The EVAP captures unburned fuel vapors from the fuel tank and reintroduces them into the fuel system. It helps in many ways, most importantly by saving fuel, minimizing environmental pollution, and preventing damage to the engine.

The pressure sensor, which is normally positioned inside or on top of the tank, works to detect the pressure in the fuel system, with the end goal of identifying leaks and defective gas caps.

This sensor is linked to the vehicle’s computer system, and in the event that there’s a leak in the EVAP, or perhaps a problem with the sensor, you will see a “check engine” signal.

Apart from that, the sensor sends info to the powertrain control module (PCM), the part that controls how the engine works and manages fuel usage.

The pressure sensor is vital for the smooth functioning of the engine through the PCM, and for the detection of leaks.

Keeping in mind all these functionalities, it’s essential to know exactly when it goes bad so the issue can be rectified promptly. In the next few moments, we will do our best to help you know if your pressure sensor has gone bad.

Let’s jump in.

Common Symptoms of a Failed Fuel Pressure Sensor

1. Diminishing power

Have you noticed a decrease in acceleration power when trying to drive faster?

You’re stepping on the gas pedal, but the vehicle isn’t gaining speed as before? That could be a sign of a bad fuel pressure sensor.

When the sensor fails, the air-fuel ratio is impaired, causing loss of power.

2. Engine warning light

Is the warning engine shining on the dash?

That could be an indication that the sensor needs attention. Here’s how that works: the computer detects the signal coming from the pressure sensor has a problem and activates the “check engine” warning, letting you know there’s an engine-related problem.

Note: there are lots of other issues that can activate the “check engine” light. Please check out this article on Lifehacker about the most common causes of “check engine” light.

3. Hard starting

If you’re consistently having trouble when trying to start your vehicle, the engine computer is possibly not getting the right signals from the pressure sensor. If the issue is not taken care of, the engine will eventually totally refuse to start.

4. Consuming too much fuel

The pressure sensor detects leaks in the fuel system, and when it fails, and then let’s say there’s a leak, which goes undetected, then unburned vapors will be released into the atmosphere. That will lead to wastage of fuel, and you will note an increase in gas expenses.

To make matters worse, the engine might not be receiving enough fuel, and there will be a drop in the vehicle’s acceleration power. So, you will be wondering – if I am using so much gas, where is it going? Yeah - it can be very annoying.

5. Stalling

If your car staling with no obvious reason, there might be a problem with fuel pressure sensor.

Let’s now look at how to replace a bad fuel rail sensor.

Replacing A Bad Fuel Pressure Sensor

This is one of the easiest car-maintenance DIY tasks you’ll ever come across. Let’s see what it entails.

You’ll need the following items for the task:

Here are the steps involved:

  1. Park the vehicle in a shaded, well-lit area and turn the engine off.
  2. Disconnect the vehicle’s battery. You can just detach the negative cable; that will disable the vehicle’s power.
  3. Jack up the car and remove the wheel on the side where the fuel tank is located. The rogue wrench will come in handy for getting the wheel off. After removing the wheel, you will probably see two pins on the lower sides of the inner wheelhouse; use the screwdriver to catch their heads and pull them out. Take care not to lose the two pins.
  4. Use the 3/8 to remove the remove the plastic screws on the inner wheelhouse and remove the house. Move the wheel well cover trim to the side. By now, you should clearly see the fuel pressure sensor; it’s at the upper side of the wheel well.
  5. To disconnect the pressure sensor, first pull out the electrical wire then pry the sensor up, removing it.
  6. Compare the old sensor with the new one. They’re alike? Great. Now, push the new sensor into place, making sure it’s seated all the way. Then, reconnect the electrical line, and make sure it clips in properly.
  7. Reinstall the inner wheelhouse as well as all the other parts that you’d removed, and that’s it; you’ve successfully installed a new fuel tank pressure sensor.

Fuel Tank Pressure Sensor Replacement Cost

The cost of a new pressure sensor depends on your car’s make and model. But, typically, you should expect to spend around 60 to 80 dollars. If you choose to have a mechanic do it for you, then it will cost you anywhere from 250 to 350 bucks (part and labor included).

If you asked us, we’d say buy the part and do it yourself. Why pay so much for such a simple installation?

Mind checking out these common questions regarding a fuel tank pressure sensor?

Frequently Asked Questions (FAQs)

1. What is the work of a fuel tank pressure sensor?

Normally mounted on the fuel tank, the fuel tank pressure sensor is a part of the fuel pump and the evaporative emissions system that detects the pressure in the fuel tank and sends the information to the vehicle’s computer system for fuel consumption regulation. It also detects leaks in the fuel system.

2. How much does the fuel tank pressure sensor cost?

The fuel tank pressure sensor ordinarily goes for 65 to 75 bucks, but if you need a mechanic to perform the installation, you might end up spending up to 350 dollars.

3. Is the fuel tank pressure sensor important? Should I worry much if it fails?

Of course, you can still drive the car with a failed fuel pressure sensor, but the risks involved are not worth taking. Realize that the pressure sensor is a vital part of the EVAP and the fuel system and indirectly, the engine.

This part helps a lot in the management of fuel consumption by the engine, and it detects leaks in the fuel system. First, a failed pressure sensor will result in unregulated fuel consumption, and you might end up using more than necessary fuel. Also, if the EVAP system develops a problem, and it goes undetected, there might be the release of dangerous vapors into the atmosphere.

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