09-12-2024, 11:03 AM
If you’re seeing both the P0171 and P0174 codes on your Ford, it means that the engine is running lean on both banks (too much air and not enough fuel). I’ve had this problem on my 2015 Ford Mustang, and it led to sluggish performance, hesitation during acceleration, and poor fuel economy. These codes are usually caused by either a vacuum leak, a problem with the Mass Air Flow (MAF) sensor, or a fuel delivery issue.
The first thing to check is for vacuum leaks. These can occur anywhere in the intake system, including hoses, the intake manifold, or the throttle body. You can use a smoke machine or carb cleaner to find leaks—spray around the intake and hoses, and if the engine speed changes, you’ve found your leak. Replace any damaged hoses or seals to resolve the issue.
Next, inspect the MAF sensor. This sensor measures the amount of air entering the engine and helps the computer adjust the air-fuel mixture. A dirty or faulty MAF sensor can cause the engine to run lean. If the sensor is dirty, clean it using MAF sensor cleaner. If it’s damaged, you’ll need to replace it.
Lastly, check the fuel system. A clogged fuel filter or failing fuel pump can restrict fuel delivery and cause lean conditions on both banks. Replacing the fuel filter or testing the fuel pump’s pressure can help identify if the fuel system is the cause.
After making these repairs, clear the codes with an OBD-II scanner and test the car. If the codes don’t return, you’ve fixed the problem. In most cases, cleaning or replacing the MAF sensor and addressing vacuum leaks will resolve the P0171 and P0174 codes.
The first thing to check is for vacuum leaks. These can occur anywhere in the intake system, including hoses, the intake manifold, or the throttle body. You can use a smoke machine or carb cleaner to find leaks—spray around the intake and hoses, and if the engine speed changes, you’ve found your leak. Replace any damaged hoses or seals to resolve the issue.
Next, inspect the MAF sensor. This sensor measures the amount of air entering the engine and helps the computer adjust the air-fuel mixture. A dirty or faulty MAF sensor can cause the engine to run lean. If the sensor is dirty, clean it using MAF sensor cleaner. If it’s damaged, you’ll need to replace it.
Lastly, check the fuel system. A clogged fuel filter or failing fuel pump can restrict fuel delivery and cause lean conditions on both banks. Replacing the fuel filter or testing the fuel pump’s pressure can help identify if the fuel system is the cause.
After making these repairs, clear the codes with an OBD-II scanner and test the car. If the codes don’t return, you’ve fixed the problem. In most cases, cleaning or replacing the MAF sensor and addressing vacuum leaks will resolve the P0171 and P0174 codes.