🔧 Accord - Oxygen Sensor Replacement

Your Accord uses two exhaust sensors: an upstream Air/Fuel (A/F) sensor (controls fuel mixture) and a downstream O2 sensor (monitors catalytic converter). Replacement is mostly about safe access, unplugging the connector, and swapping the sensor without damaging the wiring.

Difficulty Level: Intermediate | Estimated Time: 0.8-2.0 hours

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⚠️ Safety & Precautions

• ⚠️ Exhaust parts get extremely hot—let the engine cool 45-90 minutes before starting.
• ⚠️ Support the car with jack stands on solid, level ground—never rely on a floor jack alone.
• ⚠️ Do not pull on the sensor wires—only handle the connector body.
• ⚠️ If you use penetrating oil, keep it off the sensor tip and electrical connector.

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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)
• 22mm oxygen sensor socket
• 3/8" drive ratchet
• 3/8" drive torque wrench (10-100 ft-lbs range)
• 3/8" drive extension set
• Penetrating oil
• Trim clip removal tool
• Flathead screwdriver
• 10mm socket
• OBD2 scan tool (basic) (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Upstream A/F 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 into 1st gear, and set the parking brake.
• Place wheel chocks behind the rear wheels.
• Decide which sensor you’re replacing:
  • Upstream (B1S1): mounted at the exhaust manifold area, closer to the engine.
  • Downstream (B1S2): mounted after the catalytic converter, under the car.
• Tip: Spray penetrating oil and wait 10 minutes.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Identify the sensor and get access

• If replacing the downstream sensor, lift the front of the car using a floor jack and support it with jack stands.
• If a plastic splash shield blocks access, remove clips using a trim clip removal tool and/or flathead screwdriver, then remove any bolts with a 10mm socket.

Step 2: Unplug the sensor connector

• Locate the sensor’s electrical connector and release the lock tab by hand or with a flathead screwdriver.
• Separate the connector by pulling on the connector bodies (not the wires).

Step 3: Remove the old sensor

• Spray the sensor threads with penetrating oil and wait a few minutes.
• Slide the 22mm oxygen sensor socket over the sensor (it has a side cutout to clear the wire—this is why it’s different than a normal socket).
• Use a 3/8" drive ratchet and a 3/8" drive extension as needed to break it loose, then spin it out by hand.

Step 4: Install the new sensor

• Compare the new sensor to the old one (connector shape and wire length should match).
• If the new sensor threads are not pre-coated, apply a tiny amount of anti-seize compound (sensor-safe) to the threads only. Keep it off the tip.
• Thread the new sensor in by hand first to avoid cross-threading.
• Tighten using the 22mm oxygen sensor socket and a 3/8" drive torque wrench: Torque to 44 N·m (33 ft-lbs).

Step 5: Reconnect wiring and reassemble

• Route the harness the same way as the original and clip it back into any holders.
• Reconnect the connector until it clicks.
• Reinstall any splash shield hardware using a 10mm socket and reinstall clips with the trim clip removal tool.
• If the car was raised, lower it safely using the floor jack.

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✅ After Repair

• Start the engine and check for exhaust leaks (a ticking sound near the sensor area can indicate a leak).
• Use an OBD2 scan tool (basic) to clear any stored codes and turn off the check engine light.
• Test drive 10-15 minutes and verify the light stays off.
• Tip: Recheck for leaks after the test drive.

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💰 DIY vs Shop Cost

Shop Cost: $180-$450 (parts + labor)

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

You Save: $120-$230 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.8-1.5 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.