To fix a faulty oxygen sensor in a 2016 Mercedes-Benz C-Class, follow these detailed steps. This guide will help you identify the malfunctioning sensor, understand the tools required for the job, and provide step-by-step instructions to replace it.

Tools and Materials Required

• New oxygen sensor (ensure compatibility with your model).
• Socket set (often a 22mm, 7/8 inch socket is needed).
• Oxygen sensor socket (for ease of removal).
• Ratchet wrench.
• Torque wrench.
• Anti-seize lubricant (optional, but highly recommended).
• Safety gloves and goggles.

Step 1: Diagnose the Issue

1. Begin by confirming that the oxygen sensor is indeed faulty. Typically, a check engine light will illuminate on the dashboard.
2. Use an OBD-II scanner to read the trouble codes from the car's computer. Common codes like P0130 to P0167 can indicate faulty oxygen sensors.
3. Determine which oxygen sensor is faulty using the code reference; your vehicle may have more than one sensor.

Step 2: Prepare the Vehicle

1. Ensure the vehicle is parked on a level surface and the ignition is turned off.
2. Allow the exhaust system to cool if the car was running, as it could be extremely hot.
3. Disconnect the negative battery terminal to avoid any electrical short circuits or shocks.

Step 3: Locate the Faulty Oxygen Sensor

1. Identify and locate the oxygen sensor to be replaced. It's typically installed directly on the exhaust manifold or along the exhaust pipe.
2. The vehicle's manual can provide you with a detailed diagram showing the specific location of each sensor.

Step 4: Remove the Faulty Oxygen Sensor

1. Spray penetrating oil around the base of the oxygen sensor to ease its removal.
2. Unplug the electrical connector of the oxygen sensor.
3. Use the oxygen sensor socket and ratchet wrench to loosen the sensor. Turn counterclockwise until it is free.

Step 5: Install the New Oxygen Sensor

1. Apply a small amount of anti-seize lubricant to the threads of the new oxygen sensor, avoiding the sensor’s tip.
2. Hand-thread the new sensor into place to avoid cross-threading.
3. Tighten the sensor using a torque wrench to the manufacturer's specified torque settings.
4. Reconnect the electrical connector to the sensor.

Step 6: Finalize and Test

1. Reconnect the negative battery terminal.
2. Start the engine and ensure that the check engine light is off; use the OBD-II scanner if needed to clear any remaining codes.
3. Drive the vehicle for a short distance to confirm that the problem has been resolved and the car runs smoothly.

By following these steps, you should be able to replace a faulty oxygen sensor in your 2016 Mercedes-Benz C-Class. Remember to take all necessary safety precautions, and consult a professional mechanic if needed.