🔧 Challenger - Oxygen (O2) Sensor Replacement

Your Challenger uses oxygen (O2) sensors in the exhaust to help the engine computer control fuel mixture and to monitor catalytic converter efficiency. Replacing a failed sensor can fix a check-engine light, improve drivability, and prevent poor fuel control.

Difficulty Level: Intermediate | Estimated Time: 1.0-2.0 hours

Quick questions (so I target the exact sensor):

• 🧩 Which one are you replacing: Upstream (Sensor 1) or Downstream (Sensor 2)?
• 🧩 Do you have the OBD code(s) (example: P0133, P0158, P0420)?

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⚠️ Safety & Precautions

• ⚠️ Exhaust parts get extremely hot; work only on a fully cool exhaust.
• ⚠️ Support the car with jack stands; never rely on a floor jack alone.
• ⚠️ Keep the sensor wiring away from the exhaust after install to prevent melting.
• ⚠️ If you unplug sensors near hot or tight areas, disconnecting the battery helps prevent accidental shorts.

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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, pair)
• Wheel chocks
• Safety glasses
• Mechanic gloves
• 3/8" drive ratchet
• 3/8" drive extension set
• O2 sensor socket 22mm (7/8") (specialty)
• Torque wrench (10–100 ft-lbs range)
• Pick tool
• Trim clip removal tool
• Penetrating oil
• OBD2 scan tool

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Oxygen (O2) sensor - Qty: 1
• High-temp anti-seize compound - Qty: 1
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground, set the parking brake, and place wheel chocks at the rear wheels (or front wheels if lifting the rear).
• Let the exhaust cool completely (at least 1–2 hours after driving).
• If you’ll be working near the starter/large wiring or tight metal edges, disconnect the battery negative cable using a 10mm socket (add this tool if you plan to disconnect).
• Tip: Spray penetrating oil on the sensor threads early.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Raise and safely support the car

• Use a floor jack to lift the front of the car at the proper front jacking point.
• Place jack stands under solid support points and lower the car onto them.
• Give the car a gentle shake to confirm it’s stable before going underneath.

Step 2: Locate the correct O2 sensor

• Upstream (Sensor 1) sensors are before the catalytic converters (closer to the engine).
• Downstream (Sensor 2) sensors are after the catalytic converters (further back).
• Use a flashlight (from your phone is okay) and follow the sensor wire to its connector.

Step 3: Unplug the sensor connector

• Use a pick tool to lift the lock tab (if equipped), then press the release and pull the connector apart.
• If the connector is clipped to a bracket, use a trim clip removal tool to free it.
• Tip: Don’t pull on the wires—pull on the connector body.

Step 4: Remove the old O2 sensor

• Spray the sensor threads area with penetrating oil and wait 5–10 minutes.
• Install a 22mm (7/8") O2 sensor socket over the sensor, then use a 3/8" drive ratchet and extensions as needed to break it loose.
• Once loose, spin it out by hand and remove it.

Step 5: Prepare and install the new O2 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 light amount of high-temp anti-seize compound to the threads only.
• Thread the new sensor in by hand first to avoid cross-threading.
• Tighten using the 22mm (7/8") O2 sensor socket and a torque wrench: Torque to 40 Nm (30 ft-lbs).

Step 6: Reconnect wiring and secure routing

• Add a small dab of dielectric grease to the connector seal (not the metal pins).
• Reconnect the connector until it clicks/locks.
• Re-clip the harness back into its holders using the trim clip removal tool as needed.
• Confirm the wire is not touching the exhaust or hanging low.

Step 7: Lower the car

• Use the floor jack to lift slightly, remove the jack stands, then lower the car to the ground.

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✅ After Repair

• Use an OBD2 scan tool to clear stored codes and turn off the check-engine light.
• Start the engine and listen for any exhaust leaks (ticking near the sensor area).
• Test drive 10–15 minutes, then re-scan for returning codes.
• If you replaced a downstream sensor due to catalyst-efficiency codes, it may take a few drive cycles for readiness monitors to set.

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💰 DIY vs Shop Cost

Shop Cost: $200-$450 (parts + labor)

DIY Cost: $60-$200 (parts only)

You Save: $140-$250 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-1.5 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.