Range Rover oxygen sensor fault P0042

As a Range Rover owner and mechanic, I’ve experienced my fair share of issues with these luxury SUVs.

Today, I’m going to provide a guide for anyone who may be facing the specific issue of a Range Rover oxygen sensor fault P0042.

Ah, the joys of owning a Range Rover never cease to amaze me.

What models are affected?

Signs and symptoms

When a Range Rover oxygen sensor fault P0042 error occurs, the vehicle’s engine control module (ECM) registers an issue with the oxygen sensor in the exhaust system.

This error triggers the check engine light, and the driver may also experience a decrease in fuel economy.

It is also possible that the vehicle may start to consume more fuel than usual.

List of possible OBD codes

In addition to the P0042 code, other OBD codes may indicate an issue with the oxygen sensor, including:

  • P0031- Oxygen Sensor Heater Control Circuit Low Bank 1 Sensor 1
  • P0032- Oxygen Sensor Heater Control Circuit High Bank 1 Sensor 1
  • P0036- Oxygen Sensor Heater Control Circuit Low Bank 1 Sensor 2
  • P0037- Oxygen Sensor Heater Control Circuit High Bank 1 Sensor 2
  • P0134- Oxygen O2 Sensor Circuit No Activity Detected Bank 1 Sensor 1
  • P0135- Oxygen O2 Sensor Heater Circuit Bank 1 Sensor 1
  • P0141- Oxygen O2 Sensor Heater Circuit Bank 1 Sensor 2
  • P0151- Oxygen O2 Sensor Circuit Low Voltage Bank 2 Sensor 1
  • P0152- Oxygen O2 Sensor Circuit High Voltage Bank 2 Sensor 1
  • P0156- Oxygen O2 Sensor Circuit Low Voltage Bank 2 Sensor 2
  • P0157- Oxygen O2 Sensor Circuit High Voltage Bank 2 Sensor 2

Common causes

There are a few common causes of a Range Rover oxygen sensor fault P0042, including:

  • Oxygen sensor failure: This is the most common cause of a P0042 code, and it occurs when the oxygen sensor in the exhaust system fails to generate a signal.
  • Heater circuit failure: In some cases, the issue may arise from a failure in the oxygen sensor’s heater circuit, which helps adjust fuel system ratios.
  • Wiring issues: A malfunction in the power supply wire or issues with the ground connection can impact the oxygen sensor’s performance.

Can it be fixed without a mechanic?

Fixing a Range Rover oxygen sensor fault P0042 without a mechanic is possible, but it requires some knowledge of automotive repair.

If you’re familiar with the process of replacing an oxygen sensor, you can make the repairs yourself.

However, if you’re not, it’s best to take your vehicle to a certified master technician.

Parts you’ll need to fix it

The following parts will be necessary to fix a Range Rover oxygen sensor fault P0042:

  • Replacement oxygen sensor
  • Oxygen sensor socket
  • Dielectric grease
  • Anti-seize compound

Tools you’ll need to fix it

To repair the P0042 code, the following tools will be necessary:

  • Wrench set
  • Socket set
  • Ratchet wrench
  • O2 sensor socket
  • Jack and Jack stands
  • Terminal crimping tool
  • Wire stripper
  • Multi-meter

How to fix it

Follow these steps to repair a Range Rover oxygen sensor fault P0042:

  1. Disconnect the negative battery cable from your vehicle’s battery.
  2. Locate the faulty oxygen sensor. Typically you will find this sensor after the catalytic converter.
  3. Use the oxygen sensor socket to remove the old sensor.
  4. Clean off any debris or corrosion from the sensor’s threads.
  5. Apply an anti-seize compound to the threads of the new oxygen sensor before installing it.
  6. Plug the new oxygen sensor onto the wiring harness and connect the electrical connection, being careful not to over-tighten the connection.
  7. Secure the wiring harness to the vehicle’s undercarriage using zip-ties.
  8. Reconnect the negative battery cable and start the vehicle.
  9. If the P0042 code has been erased, then your repairs were successful.

Potential alternative causes

While the above-mentioned causes are the most common, there are other possible issues that may cause a Range Rover oxygen sensor fault P0042, including:

  • Issues with the catalytic converter
  • Fuel system problems
  • Exhaust leaks

FAQs

What is a P0042 code?

The P0042 code indicates that there’s an issue with the oxygen sensor heater circuit in Bank 1, Sensor 3, which can cause decreased fuel economy.

Can I ignore a P0042 code?

Ignoring a P0042 code for an extended period of time can cause issues with your vehicle’s fuel economy, so it’s best to have it addressed by a mechanic.

 

Last updated and verified on 4th September 2023

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