🔧 CR-V - Oxygen Sensor Replacement

Your CR-V has two exhaust sensors: an upstream Air/Fuel (A/F) ratio sensor (before the catalytic converter) and a downstream oxygen (O2) sensor (after the catalytic converter). Replacing the correct one restores proper fuel control (upstream) or catalyst monitoring (downstream) and can clear a check engine light.

Difficulty Level: Intermediate | Estimated Time: 0.5-1.5 hours

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⚠️ Safety & Precautions

• ⚠️ Let the exhaust cool fully before touching sensors; they get extremely hot.
• ⚠️ Support the CR-V with jack stands on solid ground; never rely on a jack alone.
• ⚠️ Unplug the sensor connector before loosening the sensor to avoid twisting/damaging the harness.
• ⚠️ If you disconnect the battery, you may lose radio presets and idle learn may be needed.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Wheel chocks
• Floor jack (rated 2-ton minimum)
• Jack stands (rated 2-ton minimum)
• 14mm socket
• 3/8" drive ratchet
• 3/8" drive extension set
• 22mm oxygen sensor socket (specialty)
• Torque wrench (10-80 ft-lbs range)
• Trim clip removal tool
• Flathead screwdriver
• Penetrating oil
• OBD2 scan tool (basic code reader)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Upstream A/F ratio sensor (Bank 1 Sensor 1) - Qty: 1
• Downstream O2 sensor (Bank 1 Sensor 2) - Qty: 1
• Anti-seize compound (sensor-safe) - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to P, and set the parking brake.
• Chock the rear wheels with wheel chocks.
• If working underneath, raise the front with a floor jack and set it on jack stands.
• Spray penetrating oil around the sensor threads and let it soak 5–10 minutes.
• Tip: Warm (not hot) exhaust loosens easier.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Identify which sensor you’re replacing

• The upstream A/F sensor (B1S1) is on the exhaust manifold at the front of the engine (top-side access).
• The downstream O2 sensor (B1S2) is after the catalytic converter (usually easiest from underneath).
• Use an OBD2 scan tool to confirm which code you have (example: P0134/P0171 often upstream; P0420 often downstream/catalyst-related).

Step 2: Disconnect the sensor electrical connector

• For top-side connectors, remove any plastic clips using a trim clip removal tool or flathead screwdriver.
• Press the connector lock tab by hand and unplug it. Tip: Don’t pull on the wires.

Step 3: Remove the sensor

• Slip the wire through the slot of the 22mm oxygen sensor socket (specialty).
• Use a 3/8" drive ratchet and extension to loosen and remove the sensor.
• If it’s stuck, apply more penetrating oil and try again after a few minutes.

Step 4: Prepare the new sensor

• Compare the old and new sensor: same connector, wire length, and thread size.
• If the new sensor threads are not pre-coated, apply a very light film of anti-seize compound (sensor-safe) to the threads only.
• Keep anti-seize off the sensor tip/holes.

Step 5: Install the new sensor

• Start threading the sensor in by hand to avoid cross-threading.
• Tighten with the 22mm oxygen sensor socket (specialty) and torque wrench.
• Torque to 44 Nm (33 ft-lbs).

Step 6: Reconnect and secure the harness

• Plug the connector back in until it clicks.
• Reinstall any wire clips/brackets you removed using a flathead screwdriver or by hand.
• Make sure the wire is routed away from the exhaust and moving parts.

Step 7: Reinstall any covers (if removed) and lower the vehicle

• If you removed a splash shield, reinstall bolts/clips using a 14mm socket (if equipped) and your ratchet.
• Lift slightly with the floor jack, remove jack stands, and lower the CR-V.

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✅ After Repair

• Use your OBD2 scan tool to clear stored codes.
• Start the engine and listen for exhaust leaks (ticking sound) near the sensor area.
• Test drive 10–15 minutes, then recheck for codes.
• If the check engine light returns with the same code, inspect the connector pins and harness routing for damage.

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💰 DIY vs Shop Cost

Shop Cost: $220-$450 (parts + labor)

DIY Cost: $60-$220 (parts only)

You Save: $160-$230 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.2 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.