P0138 is a typical OBDII code that wake up in numerous vehicles, including theFord Explorer. The password is motivated when:

The voltage in ~ the sensor remains above threshold because that 20 seconds or an ext Voltage to the sensor is to high (wiring problem, think short) negative O2 sensor chin

There are also some less likely troubles that can cause P0138. We’ll go over those below.

You are watching: 2015 ford explorer bank 1 sensor 2 location

Here’s a pretty helpful video from AutoEclinic ~ above diagnosing the code:

Ford explorer P0138 Symptoms

Typically, the just symptom the P0138 is going to it is in the service engine quickly light. In some cases, there can be other symptoms together well. These symptoms include:

turbulent running engine Smelly exhaust organization light on negative MPG

Most of the time, it’s no a malfunction risk. But, prefer anything that reasons the service engine shortly light to which it is a good idea to have actually it resolved as soon as possible. A poor air fuel mixture going through the catalytic converter

Ford explorer P0138 Causes

Here room the most typical issues that reason the P0138 password in the Ford Explorer. They room presented in order (somewhat) of most to the very least likely to cause the problem.


Damage come the Terminal– The terminal the the oxygen sensor connects to (the plug) is also reasonably susceptible come damage. You’ll want to make certain that there is voltage going come it. There’s more on that straight below. Wrong O2 Sensor– If you are acquiring P0138 after having recently changed your Oxygen sensor, it might be that the replacement is wrong or bad.

Explorer P0138 Diagnosis

It is possible to diagnose the P0138 v a multimeter. If you usage the multimeter, you’ll recognize whether or no the voltage coming to and also from the oxygen sensor is within spec, this can aid you identify if it’s your Explorer’s O2 sensor, or wiring harness that’s the issue.

If you don’t have access to a multimeter, it absolutely wouldn’t ache to examine the wiring to in between the fuse box and the Oxygen sensor first. If it ends up gift a wiring issue, it’ll save you money end buying an unnecessary O2 sensor.

You can likewise use a voltage check light to identify whether or no the oxygen sensor is getting any kind of voltage at all (they’re about $5 in ~ Walmart).

If it’s not getting any type of voltage, attach the test light to the harness plug and shake the wiring a tiny bit. If the light come on, even for a second, you recognize that you have actually a brief circuit leading to the P0138 trouble code.

See more: 2006 Ford Freestyle Serpentine Belt Diagram, Ford Freestyle: Bad Serpentine Belt


Good lucky finding whatever caused P0138 in your Ford Explorer. If you have actually anything the you would prefer to add, you re welcome feel cost-free to leave a comment below.