🔧 Murano - Oxygen Sensor Replacement (Both Sensors)

On your Murano, there are typically two oxygen sensors: an upstream (Sensor 1) that helps the engine adjust fuel mixture, and a downstream (Sensor 2) that monitors catalytic converter efficiency. Replacing both usually means working underneath the vehicle and removing tight, heat-cycled sensors from the exhaust.

Difficulty Level: Intermediate | Estimated Time: 1.5-3.0 hours

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⚠️ Safety & Precautions

• ⚠️ Let the exhaust cool completely; sensors sit in very hot pipes.
• ⚠️ Support the vehicle with jack stands; never rely on a floor jack alone.
• ⚠️ Wear safety glasses; rust/road debris falls when working underneath.
• ⚠️ Disconnecting the battery is recommended to prevent accidental shorts when unplugging connectors.
• ⚠️ If a sensor is stuck, don’t force it cold—stripping threads can damage the exhaust bung.

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 3-ton minimum)
• Jack stands (rated 3-ton minimum)
• Wheel chocks
• Safety glasses
• Mechanic gloves
• 10mm socket
• 3/8" drive ratchet
• 3/8" drive torque wrench
• 6" extension (3/8" drive)
• Oxygen sensor socket (22mm / 7/8") (specialty)
• Breaker bar (3/8" or 1/2" drive)
• Penetrating oil
• Trim clip removal tool
• Flashlight
• OBD2 scan tool

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Upstream oxygen sensor (Sensor 1 / Air-Fuel ratio sensor) - Qty: 1
• Downstream oxygen sensor (Sensor 2) - Qty: 1
• Anti-seize compound (oxygen-sensor safe) - Qty: 1
• Replacement exhaust sensor connector clips (optional) - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Chock the rear wheels with wheel chocks.
• Disconnect the negative battery terminal using a 10mm socket.
• Raise the front of the vehicle with a floor jack and support it with jack stands under the proper lift points.
• Spray sensors the night before if rusty. Use penetrating oil at the sensor threads (where the sensor meets the exhaust pipe).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Locate both oxygen sensors

• Use a flashlight to find the sensors on the exhaust.
• Upstream (Sensor 1) is typically located before the catalytic converter (closer to the engine).
• Downstream (Sensor 2) is typically located after the catalytic converter (further back).

Step 2: Unplug the upstream sensor connector

• Follow the upstream sensor wire to its electrical connector.
• Release any harness clips using a trim clip removal tool.
• Press the connector lock tab by hand and separate the connector. Don’t pull on the wires.

Step 3: Remove the upstream sensor

• Spray the sensor threads again with penetrating oil and wait a few minutes.
• Install the oxygen sensor socket (22mm / 7/8") over the sensor and attach a 3/8" drive ratchet and 6" extension if needed.
• Break it loose using a breaker bar if it’s tight, then spin it out with the ratchet.
• If it feels like it’s seizing, tighten slightly then loosen again (small back-and-forth) using the ratchet.

Step 4: Install the new upstream sensor

• Compare the old and new sensor connectors to confirm they match.
• If the new sensor threads are not pre-coated, apply a tiny amount of anti-seize compound (oxygen-sensor safe) to the threads only. Keep it off the tip.
• Thread the sensor in by hand first to avoid cross-threading (damaging the exhaust threads).
• Tighten using the oxygen sensor socket (22mm / 7/8") and torque wrench: Torque to 40 Nm (30 ft-lbs).
• Reconnect the electrical connector until it clicks, then re-secure harness clips using the trim clip removal tool.

Step 5: Unplug the downstream sensor connector

• Locate the downstream sensor connector by following the sensor wire.
• Release clips using a trim clip removal tool and unplug the connector by hand.

Step 6: Remove the downstream sensor

• Apply penetrating oil at the threads and let it soak a few minutes.
• Use the oxygen sensor socket (22mm / 7/8") with a ratchet and/or breaker bar to loosen and remove the sensor.

Step 7: Install the new downstream sensor

• Apply anti-seize compound (oxygen-sensor safe) to threads only if not pre-coated.
• Start threads by hand, then tighten using the oxygen sensor socket (22mm / 7/8").
• Tighten with a torque wrench: Torque to 40 Nm (30 ft-lbs).
• Reconnect the electrical connector until it clicks and re-clip the harness using the trim clip removal tool.

Step 8: Reconnect battery and lower the vehicle

• Reconnect the negative battery cable using a 10mm socket.
• Raise slightly with the floor jack, remove jack stands, then lower the vehicle.
• Remove wheel chocks.

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✅ After Repair

• Use an OBD2 scan tool to clear stored trouble codes (if any).
• Start the engine and listen for exhaust leaks (ticking sound) near the sensor areas.
• With the engine idling, verify the Check Engine Light stays off.
• Test drive 10–15 minutes and re-scan using the OBD2 scan tool to confirm no codes return.

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💰 DIY vs Shop Cost

Shop Cost: $300-$700 (parts + labor)

DIY Cost: $120-$350 (parts only)

You Save: $180-$350 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.

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🎯 Ready to get started?

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