Error Code P1167 is described as Air/Fuel Ratio Sensor 1 Heater System Malfunction. This means the maximum voltage specified by the manufacturer for the vehicle has not been reached.

This code is a generic trouble code, meaning it applies to all vehicles equipped with OBD-II system, especially vehicles made since 1996 up to present. Specifications on the definition, troubleshooting, and repairs of course, vary from one make and/or model to another.


Error Code P1167 is set when the maximum voltage from the sensor is not reached to the specified voltage. This refers to a heater malfunction code in the A/F sensor.

Common Symptoms

Triggered Check Engine light is the most common symptom for this error code. And in most cases, that’s pretty much it. In other makes and/or models, the vehicle may suffer from lack of power, jerking or stalling. Other symptoms include:

  • High fuel consumption
  • Excessive smoke from the exhaust

Possible Causes

There are many possible factors that may cause this error code to take place. Some of the most common causes are:

  • Faulty Heated Rear O2 Sensor Bank 2
  • Open or Shorted Heated Rear O2 Sensor Bank 2 harness
  • Poor electrical connection in Open or Shorted Heated Rear O2 Sensor Bank 2
  • Bad Fuel pressure
  • Intake air leaks
  • Faulty Injectors

How to Check

Check the wiring to the sensor; look for stripped wires or signs of rubbing and chaffing on the body. Check all the connections that may have loosened or disconnected due to vibrations at some point.

Pull the PCM fuse (30A) under hood for a few minutes then pop it back in again. Reset the PCM. Your vehicle will re-learn the adaptive fuel trim, so expect a little bit of loss in your fuel economy.

If the code comes back, then that means there is no wiring problem, rather a problem in the sensor. This is where you may need to replace your sensor.

If it still doesn’t fix the problem, then it’s time to take your vehicle back to the dealership and have it thoroughly checked by a certified technician.

How to Fix

Replacing the Rear Oxygen Sensor usually solves the problem. If it doesn’t, then other possible repairs include:

  • Repair or replacement of A/F sensor or relay
  • Repair or replace bad wiring

Other common suspect areas for this error code include:

  • Electrical harness and connectors
  • High pressure pump
  • Diesel fuel high pressure connector
  • Engine PCM

As with other error codes, it is important that if you had any maintenance or repairs done make sure all sensor plugs and wiring has been plugged back in and fastened correctly.