2015–2021 Lexus NX

2015-2021 Lexus NX — Replace Oxygen Sensor

By Ray Delgado ✓ Certified Mechanic · Published Sep 21, 2026 · Updated Oct 22, 2026

🔧🔧🔧 Advanced 1-2 hours $231 DIY 2 views

Save $169 by doing it yourself! Shop cost: $400

Quick answer: Replace Oxygen Sensor on a 2015–2021 Lexus NX is rated Advanced and takes about 1-2 hours. You'll need 5 tools for this job, and parts cost about $231. This guide walks you through the full job step by step, including the mistakes to avoid.

Quick Video Tutorial

Parts You Need

Total Cost

$230.95

Part Name	Part Number	Price	Buy
Oxygen Sensor	OSA61773	$80.95	Amazon
Oxygen Sensor Simulator	—	$150.00	Amazon

About prices: shown prices are typical retail averages and change frequently; cheaper alternatives may be available. Confirm the current price before buying.

💡 Pro tip: Order all parts at once to save on shipping

Step-by-Step Instructions

Follow these steps carefully

Identify which O2 sensor and cool the exhaust

Confirm whether you're replacing an upstream (pre-cat) or downstream (post-cat) sensor and match the part to that location. Work only on a cool exhaust. Wear gloves and eye protection; raise and support the vehicle if underbody access is required.

Disconnect the sensor connector

Trace the sensor pigtail to its connector — often clipped to the frame, valve cover, or transmission tunnel. Unplug it and free any harness clips so the lead can rotate with the sensor during removal.

Remove the old sensor

Use an oxygen-sensor socket or appropriate wrench. Apply penetrating oil if seized and allow it to soak; heat carefully only if needed and safe. Turn the sensor out — avoid damaging nearby wires, heat shields, or catalytic-converter threads.

🔧 Mechanic's note — Tom Becker

I've learned to give that penetrating oil real time to work — a seized O2 sensor will strip the bung threads right out of the pipe if you muscle it. Heat is a last resort, and keep the flame off the wiring.

Prepare the new sensor

Compare thread pitch and connector to the old unit. Most new sensors include anti-seize on the threads — do not get anti-seize on the tip or protection tube. Never clean or paint the sensing element.

🔧 Mechanic's note — Ray Delgado

I've been burned enough times that I always keep anti-seize off the sensor tip — it poisons the sensing element and you'll get lazy readings. Threads only, and most new sensors come pre-coated anyway.

Install and torque the new sensor

Thread the new sensor by hand to avoid cross-threading, then torque to spec — often around 30–40 N·m; use the value for this vehicle. Route the pigtail away from hot exhaust and moving parts, and reconnect the connector until it locks.

Clear codes and verify fuel trim

Lower the vehicle if raised. Start the engine and confirm the heater circuit runs with no exhaust leak at the bung. Clear related codes with a scan tool and road-test; monitors may need a complete drive cycle before readiness returns.