P0172 Ford Code: What It Is and How to Fix It

Working with trouble codes is no easy matter, especially because there are so many of them. Just amongst ‘P’ as in powertrain-related codes, you have almost thousands of them. You may have heard of the P0172 error code in other vehicles, but what makes things a little more complicated is that the symptoms and diagnosis of the code can also differ depending on the car model.

In today’s discussion, we will be delving into the details of the P0172 Ford error code. To give you a rough idea, this code pops up when there is an issue with the fuel-air ratio. We will be discussing more what this code is and how to clear it, along with more important things, all over here!

P0172 Ford

What does P0172 Ford Mean?

The meaning of the P0172 trouble code remains the same for Ford vehicles, just as it does for any other models. If you see this can after plugging in your OBD II scanner, then it means that the ECU, also known as the engine control unit, has received a signal that the fuel has become too rich in the bank 1 of the engine. This area of the engine houses the number 1 cylinder. 

You may already know this, but the term ‘too rich’ means that too much fuel and too little air are present in the fuel mixture. Running your Ford with such a fuel mixture can gradually damage all the important components of your engine, which will reduce its lifetime. 

To give you more context, the optimum air-to-fuel ratio is 14.71:1. When the ratio increases or decreases from the aforementioned number, your car will not be functioning as smoothly anymore and will start malfunctioning in many ways. Learning about the p0171 ford code may help you understand the issue even better.

What are the Symptoms?

Like we have said, there are many ways your car will start to malfunction when the fuel becomes too rich in the bank 1 of your Ford. If you know the symptoms of this issue ahead of time, then you will be able to save yourself from getting into a bigger mess. Here are some symptoms that you will usually experience with a P0172 error code in your Ford:

Flashing Engine Light

Most of you probably already know this by now, but whenever any trouble code is triggered, the first thing the engine control unit will do to notify you is turn on the check engine light. Although you won’t be able to tell if you have the P0172 code by looking at the engine light, it is the first and most obvious sign that you should run an OBD2 scan.

Higher Consumption of Fuel 

The consumption of fuel increases whenever there is an issue with the air-to-fuel ratio of the gasoline mixture, not just for the P0172 trouble code in Ford. As a result, the fuel economy becomes much worse, and you’ll have to fill up your fuel tank more often. However, this symptom could also mean a p0022 ford f150. So, you’ll need to look for other more obvious signals.

Dark Smoke From the Exhaust

If things get a bit more severe inside your Ford’s engine, and the fuel becomes EXTREMELY rich, you may see black smoke evolving from the exhaust of your car. This symptom is a clear sign of the P0172 code, and for you to stop your car immediately and call a mechanic.

Rough Idling 

Whenever something is going on with your engine, you are most likely to have a rough idling engine. The car can’t produce the maximum power because of the improper fuel-air ratio, and this causes the engine to jerk, which makes the car have a rough idle. 

Hesitating to Accelerate & Low Power

The drop in power of your Ford’s engine is commonly seen in pair with a rough idle. As mentioned before, not all the cylinders of the engine can produce the right amount of power with this code. Because of this reason, you will also notice that your engine struggles to accelerate a lot. 

Exhaust giving off Strong Fuel Smell 

There are many issues that this trouble code could cause that could result in this obnoxious smell, which some say is like rotten eggs, comes from the exhaust. You should stop your car when you start getting this smell, or in some rare cases, this could lead to an accident. 

Possible Causes for P0172 Ford

From a small vacuum leak to major faulty sensors, the severity of the cause making the P0172 Ford code show up varies from vehicle to vehicle. Below we have listed down most of the probable reasons why you may find yourself with a P0172 code.

Defective Front Heated O2 Sensor

A major reason for this ‘too rich fuel mixture is when the front heated oxygen sensor starts to malfunction. So, this sensor will then tell the ECU that more oxygen has entered the cylinders than the real amount. Since the amount of oxygen is proportional to the amount of air in the gasoline mixture, this will make the air-to-fuel ratio lower than 14.71:1. The defective is a major reason behind P0340 Ford F150 code as well.

Contaminated or Failed Mass Airflow Sensor

The issue raised by a dirty or faulty mass airflow sensor is almost the same as the oxygen sensor. The mass air sensor is supposed to calculate the total volume of air entering the engine. So, when it becomes very dirty or defective, it cannot do this calculation correctly. 

Faulty Spark Plugs

You might notice that your spark plugs have become worn and bad when trying to clear this code. Bad spark plugs have a direct correlation with inefficient burning of fuel, so this is also one of the reasons why your fuel economy becomes so poor when you have a P0172.

Improper Fuel Pressure

If the fuel pressure isn’t correct, it could also lead to too much fuel getting into the combustion chamber and making the mixture rich. It has the capability to lead to OBD P0172 BMW code as well.

Vacuum Leak

Some people think that vacuum leaks can only make the fuel too lean, but in some cases, they can also make it run too rich. 

Leaking Fuel Injectors

If the fuel injectors in your Ford are leaking, they will increase the amount of fuel coming into the combustion chamber of the engine. Thus, resulting in a richer mixture and triggering the P0172 code.

How to Diagnose the P0172 Ford Code

How to Diagnose the P0172 Ford Code

For someone to be able to do a complete diagnosis of any error code calls for a lot of technical automobile skills and a lot of tolerance since it requires a lot of trial and error. Diagnosing the code properly is one of the important things to do when attempting to clear the P0172. 

That is why we will suggest you let a skilled mechanic do it. In this way, you will avoid any unnecessary repairs from damages you could cause when trying to do the diagnosis on your own. 

The best way to do the diagnosis is to check the causes that have the easiest fixes. So, we would suggest you tell your mechanic to start by checking the MAF and O2 sensor to see if they’re clean and operating properly. Then, you want them to search for vacuum leaks. They will also have to do a fuel pressure test.

As a blocked air intake system can also result in this code, the mechanic should also see if the air filters are clogged. 

Cost of Diagnosis 

Due to the complexity of the diagnosis of this error code, you can’t do it for free by doing it yourself. You’ll have to spend some money to pay a mechanic. This is 100% worth it because damages you could accidentally do to the engine might cost you a lot. 

Depending on the mechanic workshop you take your Ford to, the diagnostic fee will vary quite a bit. If we were to give you an approximate cost, then we would say that the labor cost of this diagnosis would be roughly $120. 

How to Fix P0172 Ford

Depending on what underlying issue your car has, the fixing process for this code to be cleared will differ. There’s not much you can do here except see if the mechanic is doing their job properly. Your mechanic will know what to do after the completion of the diagnosis, so you can relax. 

If the workshop you take your car to is very reliable, then you don’t even have to be present during the repair. However, if it’s a new place, then stand there and observe what they’re doing.

Finadl Words

By now, you should have a good grasp of what the P0172 Ford trouble code is and the necessary steps you have to take to solve it. Our main tip for this entire situation would be to do the OBD2 scan as soon as you see the flashing engine light and then take it to a good workshop. Don’t be lazy and don’t push back taking your car to the mechanic to clear this code, or else you’d be putting your safety at risk!