How To Replace a Ford Fusion Oxygen Sensor

How To Replace a Ford Fusion Oxygen Sensor


The upstream 02 sensor in your 2.5 liter Ford Fusion is a vital part of your engine system. Your primary Fusion Oxygen Sensor is mounted in your exhaust header. It’s designed to analyze your exhaust fumes and report just how rich ( too much fuel ) or lean ( not enough fuel ) your engine is running. This four wire oxygen sensor is comprised of 2 heater wires, a ground wire and a signal wire.

When your Ford Fusion Oxygen Sensor is fouled or begins to fail, your engine computer won’t be able to properly correct your fuel trims. This can cause your engine to idle poorly, run rough or even cause your transmission to shift harshly.

Today I will be showing you how to replace your Fusion Oxygen Sensor in a 2014 2.5 liter equipped Fusion. This vehicle has a fouled front or primary 02 sensor, and you can replace this unit easily using hand tools.

How To Replace a Ford Fusion Oxygen Sensor

Because the 2.5 liter engine in your Ford Fusion has the exhaust facing towards the rear, it’s a good idea to work on your car when it’s cold.

Symptoms of a failed Ford Fusion Oxygen Sensor

  • Bad gas mileage
  • Check Engine Light ON
  • Harsh shifting transmission
  • Black smoke from tailpipe

How to Replace your Ford Fusion 02 sensor

To begin replacing your Fusion primary 02 sensor, you will need a 22mm open end wrench or a 02 socket. You can rent an 02 socket from your local auto parts store or simply purchase a 22mm open end wrench.

Open your hood and locate the white four pin primary upstream 02 sensor harness. Pull up on the harness to free the Fusion oxygen sensor connector.

How To Replace a Ford Fusion Oxygen Sensor 1

Depress the oxygen sensor and disconnect the upstream 02 sensor for your vehicle. Once you have the 02 sensor unplugged you can begin unscrewing the primary oxygen sensor.

How To Replace a Ford Fusion Oxygen Sensor 3

Now that your primary Fusion Oxygen Sensor is unplugged, you can proceed to unscrew the 02 sensor. Take your 22mm open wrench and unscrew the upstream 02 sensor next.

How To Replace a Ford Fusion Oxygen Sensor 2

Once you have the 02 sensor removed you can install your replacement Fusion oxygen sensor. Make sure to lightly apply a layer of anti-seize to the threads of the primary 02 sensor. Screw in the 02 sensor carefully so you don’t cross thread your exhaust piping.

And after you’ve installed your upstream 02 sensor replacement, you must use a OBDII scan tool to erase any stored DTC codes. This tool can help you remove any check engine light codes from your Ford Fusion dashboard.

How To Replace a Ford Fusion Oxygen Sensor 4

Have any questions about our How To DIY guide to your 2014 Ford Fusion upstream 02 sensor? Leave them for us below and let us know!