OBD2 error code P0172: How to solve fuel system issue?

The fuel and air ratio is essential for the car engine. And it would help if you were careful that the percentage of this mixture remains the same all time. If this number changed by any chance, the scanner found an issue in the engine system and sent a trouble code on the car’s dashboard. When in the bank, 1 of the car gets a richer amount of air than the ideal one, sending the error code P0172 in the display. And here we are talking all about the details of this trouble code of the car.

What is the meaning of error code P0172?

The error code P0172 pops when extra gasoline is present in the engine air/fuel mixture, determined by the car’s ECU. The ratio of this mixture is around 14:7:1; it also provides the car engine’s performance and the fuel’s economy. 

So when the car system finds there is extra gasoline on the exhaust gas in the combustion chamber, it gets something not usually happens in there so that the ECU starts working and uses a number of instruments like mass air flow sensor/MAF, oxygen sensor, manifold absolute pressure to measure the number of air/fuel ratio on the engine. Mainly an O2 sensor is used to monitor this number from the exhaust gas, calculating from oxygen and carbon monoxide there. This ratio also helps to learn the amount of the highest power output and the lowest fuel consumption rate. 

Air and fuel are the two main things in the internal combustion process. So it’s really important to supply the proper amount of these two things in this chamber if you want the ignition to work properly. Otherwise, the engine consumes more fuel but lessens the engine performance. 

The ECU is the head of all systems, so it can check the ratio of air/fuel and change the rating. But that’s not the solution to this error code. The user must find the main reason and, after that, solve it. And in this code, rich means extra gasoline in the mixture and also not enough oxygen on the engine to minimize the ratio of air and fuel. 

What are the reasons behind the error code?

Before you solve the trouble code P0172, you just need to know the core of the issue, and that’s why you need to know the reason behind this issue. After learning about this, you can easily get a solution. And the possible reasons are given below:

  • Don’t change the oil for a long time or contaminated engine oil,
  • Dirt on mass air flow or MAS sensor,
  • Leakage in fuel injector,
  • Damaged O2 sensor,
  • bright CEL,
  • damaged regulator,
  • the issue in the air 
  • Excess fuel pressure or damaged pressure regulator,
  • A vacuum leakage,
  • Block anywhere of the air intake system,
  • Restricting on thermostat or coolant temperature sensor got damaged,
  • Clog on exhaust components like the catalytic converter, muffler, exhaust pipe, etc.,
  • Loose connection or damaged wiring,
  • Issues with Powertrain control module or PCM.
  • Old spark plugs.

Common symptoms:

The error code P0172 is not good news for any car user. And to ensure the error code, there are many symptoms are noticeable, like:

  • Illuminated car’s check engine light,
  • Extra fuel consuming, 
  • Lack of engine power,
  • The hesitation in starting the engine,
  • Misfiring,
  • The engine leaves black smoke from the exhaust side,
  • Strong fuel odor can come from the inside cabin of the car.

 How to diagnose the error code P0172?

There is some easy way to find the issue on the car. But examine every part of this error very carefully. To ensure the issue, don’t change or replace any part of the car. And the step-by-step error code diagnostic process is given below:

  • To find the code from the car, every mechanic and also DIY people use an OBD scanner. And after getting the code from there, they first perform a fuel pressure test. 
  • Use a non-operating injector diode or NOID light to check the pulse of the fuel injector,
  • After that, start visual inception on the vacuum area of the car, and find if there is any loose connection, damaged wire, or leakage.
  • Check the mass air flow or MAF sensor and whether the o2 sensor is working correctly or not.
  • Look over the air intake system, is it blocked or clogged, or working properly?

So these are the primary things you must need to diagnose to find the rich gasoline issue in the car, and if you know about your vehicle, you can easily find the problem quickly. But if you still don’t see the issue, call the mechanic to get help from them.

Avoid Mistakes

Most of the time, technicians make mistakes in diagnosing the issue. Like they don’t need to examine the car’s coolant sensor or cooling system. When the car is turned off and the engine is not working, then it remains cold, and fuel is mainly used to heat that up but at an expected temperature. And sometimes, ECU mistakes this and doesn’t find the issue from there. Because the engine is running cold, and that’s why it takes more fuel than average.

How to fix the error code P0172?

There are some simple steps you need to follow to solve the error code from the car. And those are given below:

  • Examine all vacuum and PCV hoses. Find if there is any leakage or loose connection in the system. If you find it, then repair this as soon as possible. But if the whole system just got damaged, replace it with a new one.
  • Check your MAF sensor and clean that area. If you don’t find the location of this sensor on the vehicle, then take help from the car manual. Use spray cleaner or clean all the electronics in there. But when you clean that area always is careful. Don’t damage any wire or connection while cleaning that area.
  • Investigate the entire fuel lines. If you find any cracks, leaks, or pinches, repair them immediately,
  • Examine the pressure of fuel on the fuel rail,
  • Check if the fuel injector gets old or dirty. If it’s dirty, clean it very gently, and if it gets old, then install a new one.
  • Search all the elements of the exhaust system, including the oxygen sensor; if you find any issue there, like damage or leakage, repair it. But if it’s damaged too much, then replace it.

If you don’t know every part of the car but still want to do it yourself, you can read the OBD manual to fix the issue and find all aspects of the vehicle, and get help from the technician bulletins. It not only contains every detail of the car but also helps you to get out of this type of issue. But driving a car with this issue is not recommended. When you don’t find the issue or solve it, please don’t change anything in there. Just go to the car mechanic; it will cost you some money but save some time and also ensure the security from error.

How serious is this error code P0172?

The error code of the P0172 is not the normal type. If your car has this error, it can’t pass a state vehicle inception. And the main reason for this failure is the blinking check engine light. On the other way, if the car’s air and fuel ratio increases, the engine starts to make black smog. And it also comes out from the car in the exhaust area. This makes you uncomfortable and pollutes the air of the environment. That’s why it’s highly recommended to fix the issue P0172 as soon as possible.

Repair cost:

This cost depends on how serious the issue is and varies from place to place. But here I just try to give you an idea about how much money you need to get prepared to solve this error code from the car. Fixing the leakage of the vacuum need $100 to $200, and cleaning the dirty MAF cost around $100. If you want to replace the old MAF, it will cost not more than $300. If the issue is related to the fuel pump, it needs $1700 to replace. Changing the damaged regulator cost not more than $400, and the last one is an issue with air fuel sensors that need around $300.

Here is the basic expense to fix this issue from the car. But try to solve the issue as soon as possible. If you neglect this, it starts to damage the car engine, and after some time, you won’t be able to drive your car.

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