P0171 Code Ford F150: Meaning, Symptoms, & Fixes

An ODBII scanner can be used in a Ford F150 to scour and uncover possible issues that may plague your pickup truck. The codes help to point you in a particular direction, so you don’t have to waste as much time trying to find the source of the problem.

One of the most common error codes you may encounter is the P0171 Ford F150. Since you’re likely to encounter it, you want to know what it means, why it can occur and how to fix it. This article will detail just that.

P0171 Code Ford F150

Definition Of P0171 Ford F150

The p0171 is an engine code that can be obtained by scanning using an ODBII scanner. It is not necessarily exclusive to the Ford F150 truck and sees use in other models and vehicles. This code represents a problem in the exhaust system and can be connected to the $7E8 Engine Code. The location of this problem usually stems from the fuel trim system bank. 

What Does P0171 Ford F150 Mean?

This engine code refers to a lack of oxygen in the exhaust system. The lack of oxygen in the exhaust system of your pickup truck is usually referred to as the “lean” condition. Oxygen is needed for combustion to take place, so when there is a lower amount of oxygen entering the internal engine, the mixture won’t ignite properly.

Engines rely on an appropriate ratio of air and fuel to work properly. Lower oxygen levels will affect that ratio and end up causing performance issues for your car. This ratio is usually maintained by the Powertrain Control Module of your car.

To compensate for lower oxygen levels, the engine will usually tend to draw more oxygen in to ensure it is properly working. When the engine is doing this, you’ll usually notice an indicator light up warning you of this. The Ford F150’s ECM will either draw in more oxygen or add more fuel to provide more combustion to keep the truck going. The code P0171 also signifies the ECM adding in more fuel during a lean condition. 

Although the problem is not as severe as some other engine issues, it is recommended to treat it as early as when you see the signs. The reason is that the engine drawing in more fuel or oxygen will put heavy stress on the vehicle. This stress can damage the spark plugs of your car, and since it affects the exhaust system, the damage can extend to your catalytic converters as well. 

Possible Causes Of P0171 Ford F150

Now, let’s look at what can cause this code to arise. Some common reasons as to why this happens include:


Since the error code refers to lower oxygen levels, one of the common causes is leaks causing loss of oxygen. The vacuum or PCV hoses can get torn or damaged and end up having leaks. This will result in air being lost until the holes are patched. This can also cause a DTC P0172 in Ford.

Your exhaust system can also leak, although this is on the rarer side. 

Faulty Sensor

If your oxygen sensor is faulty, it might end up signaling low oxygen levels, which will cause the ECM to tell the vehicle to draw more oxygen. This faulty reading will end up damaging your truck, so it is important to check the functionality of your oxygen sensor.

Similarly, your airflow sensor can also get clogged and become faulty. It is important to clean and unclog it, or you will end up getting faulty readings using your sensor. 

Fuel Pump Not Operating Properly

Since the p0171 usually indicates low oxygen levels, one reason for it happening can be due to a weak fuel pump. If your fuel pump is not pumping oxygen properly, you’re going to end up with an improper ratio, and your engine won’t perform ideally. Similarly, your fuel injectors can also be clogged and, as a result, won’t be able to keep up with your engine unless they’re cleaned and unclogged.

Symptoms Of P0171 Ford F150

The symptoms of p0171 aren’t too acute and, as a result, can be hard to identify at times. In addition, sometimes they’re confused with the signs of ford code p1131. Some symptoms you can come across include:

  • Performance or mileage decrease
  • Engine misfiring occasionally
  • The vehicle will often shake violently at times
  • Spark plugs get discolored

How To Diagnosis the P0171 Error Code In Ford F150?

How To Diagnosis the P0171 Error Code In Ford F150

Diagnosing this code isn’t too difficult. You first want to start with the fuel injectors and oxygen sensors. Make sure to check if they are working properly or not or if they need replacing. Next, you want to check your fuel pump to ensure that it is pumping enough fuel.

Alongside these, you should extensively look for any signs of a leak. Leaks can be difficult to detect at times, so you need to be thorough in your search.

How To Fix the Error Code?

Most fixes for this code involve you changing out some parts like faulty sensors or your fuel pump. Other fixes can include you needing to unclog and clean up some parts of your engine to ensure proper airflow within your engine. 

As for fixing leaks, sometimes you can patch up the leaks in your truck’s pipes. However, these are usually not full fixes, and sometimes a better fix is to replace the faulty pipes for better longevity.

How Much Does It Cost To Fix?

It depends on how extensive your repair work is and how much you’re paying for labor. Usually, repair costs can go from anywhere from 80 to 150 dollars, depending on what you’re replacing. It can go up to 180 dollars at max if you include labor costs.

Common Mistakes During Diagnosis

There aren’t too many mistakes to make since diagnosing the issue is relatively easy. The main thing you should keep in mind is to try out various oxygen sensors or fuel sensors to make sure there aren’t any calibration issues with your readings. 


After reading this article, you should be more familiar with the p0171 Ford F150 code. Although not the most problematic code, it can spiral into a big issue if left unchecked. So make sure to call your reliable mechanic if you notice performance issues with your car. 

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