🔧 Accord - Oxygen Sensor Replacement

Your Accord has more than one oxygen sensor: an upstream sensor (also called an air/fuel ratio sensor) before the catalytic converter, and a downstream sensor after the catalytic converter. The replacement steps are similar, but the sensor location and access are different.

Difficulty Level: Intermediate | Estimated Time: 0.7-1.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cold exhaust—hot parts can burn you.
• ⚠️ Support the car with jack stands; never rely on a jack alone.
• ⚠️ Keep the sensor wires away from the exhaust when reinstalling.
• 🔋 Battery disconnect is not required, but it’s safer to unplug sensors with the key OFF.

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🔧 Required Tools

You'll need the following tools for this repair:

• Floor jack (rated 2-ton minimum)
• Jack stands (rated 2-ton minimum)
• Wheel chocks
• Safety glasses
• Mechanic gloves
• 3/8" drive ratchet
• 3/8" drive extension set
• 22mm oxygen sensor socket (specialty)
• 22mm box-end wrench
• Torque wrench (10–80 ft-lbs range)
• Trim clip tool
• Penetrating oil

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Upstream air/fuel ratio sensor (Sensor 1) - Qty: 1
• Downstream oxygen sensor (Sensor 2) - Qty: 1
• Replacement exhaust heat shield clips - Qty: 2-6

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks behind the rear tires.
• Let the engine and exhaust cool fully (at least 1 hour).
• Spray penetrating oil on the sensor threads and let it soak 10–15 minutes.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Confirm which oxygen sensor you’re replacing

• Tell me which one: Upstream (Sensor 1, before the catalytic converter) or Downstream (Sensor 2, after the catalytic converter).
• If you have a code, share it (example: P0134, P0420). This helps ensure you replace the correct sensor.

Step 2: Safely raise and support the car (for best access)

• Use a floor jack to lift the front of the car at the front center jack point.
• Set the car onto jack stands at the left and right pinch welds.
• Give the car a gentle push to confirm it’s stable before going underneath.

Step 3: Locate the sensor and unplug the connector

• Use safety glasses and a light source so you can see the harness routing clearly.
• Follow the sensor wire to its electrical connector.
• Release the connector lock and unplug it by hand; use a trim clip tool if the harness is clipped to a bracket.
• Tip: Don’t pull on the wires.

Step 4: Remove the oxygen sensor

• Fit a 22mm oxygen sensor socket (specialty) over the sensor (the slot allows the wire to pass through).
• Use a 3/8" drive ratchet and 3/8" drive extension to break it loose and unthread it.
• If space is tight, use a 22mm box-end wrench to crack it loose first.

Step 5: Install the new sensor

• Thread the new sensor in by hand first to avoid cross-threading (damaging threads).
• Tighten using the 22mm oxygen sensor socket (specialty) and torque wrench.
• Torque to 44 Nm (33 ft-lbs).
• Route the harness the same way as the original so it can’t touch the exhaust.

Step 6: Reconnect and secure the wiring

• Plug the connector in until it clicks.
• Reinstall any harness clips using the trim clip tool to guide them in without breaking them.

Step 7: Lower the car

• Use the floor jack to lift slightly, remove the jack stands, and set the car back down.

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✅ After Repair

• Start the engine and listen for exhaust leaks (a “ticking” sound near the sensor area).
• If the check engine light was on, clear codes with a scan tool and verify they don’t return after a short drive.
• Recheck that the sensor wire is not near any hot exhaust surfaces.

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💰 DIY vs Shop Cost

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

DIY Cost: $70-$220 (parts only)

You Save: $150-$230 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.5 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.