Ford Mustang P0174 Trouble Code – Test your MAF

When you’ve got a OBDII trouble code for a Ford Mustang P0174, this means that there’s a problem with your mass air flow meter. This can signify a problem with the sensor, or that your Mustang MAF has fouled or become dirty. The Ford Mustang P0174 trouble code is a generic OBDII check engine light that represents a too lean condition. The specific wording for this code is Bank 2 Too Lean.

This code is triggered in your Ford Mustang when your engine is running and your Ford Powertrain Control Module recognizes that the exhaust stream in your Bank 2 oxygen sensor is reading far more air as opposed to fuel. This means your engine is running lean, or not receiving enough fuel to the combustion chamber. Although the Ford Mustang P0174 can mean something else is at fault, typically it’s a mass air flow related issue.

Today I will be showing you how to test your Mustang MAF sensor in a 1996 Ford Mustang with a 3.8 liter engine in it. To complete this guide you’re going to need a digital multimeter. This model mounts the maf sensor inline with your intake tract, and it’s connected by way of a four pin engine harness.

Ford Mustang P0174 Trouble Code 1

Symptoms of a Ford Mustang P0174

When you have this trouble code, it can cause several different symptoms that you may confuse or misdiagnose. Here’s just a few symptoms of this common check engine code.

  • Severe lack of power
  • Engine pre-detonation (pinging)
  • Fouled oxygen sensor
  • Poor gas mileage

Testing your Ford Mustang mass air flow sensor

Using the Mustang MAF sensor wiring schematic below, you’ll be using your multimeter to check for power and ground. This is to make sure that your MAF has not failed due to lack of power or problems with your fuses, relays or wiring. The wire to begin with is the RED wire, or WIRE 1. This MAF sensor test can only be done with your key turned to the ON position. Now disconnect the MAF sensor connector, and test the RED wire for a 12 volts circuit signal with your multimeter.

Ford Mustang P0174 Trouble Code 4

The next wire you’ll be checking is WIRE 2, which is a BLACK wire. This wire should return a ground signal, which is from the power ground. Now check WIRE C which is a WHITE wire with a BLACK stripe, or a YELLOW wire, depending on the year of your V6 Ford Mustang. If your multimeter can read Hertz and KHertz, you can measure the operation of your mass air flow signal by testing at WIRE 4.

Your MAF tests out but the P0174 Trouble code is still present

If your mass air flow meter checks out, the chances are that your MAF has become dirty. You can use MAF cleaner to clear away any debris or to improve the operation of your vane meter. Make sure to use a proper MAF cleaner or electronics cleaner and avoid using brake cleaner as it can leave residue. Before re-installing your MAF sensor, make sure that your mass air flow meter is completely dry.

If you have cleaned your MAF and tested it but the lean condition is still present, check your vacuum hoses and intake pipes for leaks. Leaks or loose clamps can cause more air to enter the system. Because these leaks are AFTER your mass air flow sensor, this is unmetered air that your PCM has no clue about. These leaks can cause a lean condition and trigger your P0174 code.

Have any questions about this Ford Mustang P0174 guide? leave them below and let me know!

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