my Volkswagen Golf MK7 (2015-2019) has a P0135 code what does that indicate

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the vehicle's battery to prevent electrical shock.
• Allow the engine to cool completely before starting work.

2. Remove the Oxygen Sensor

• Locate the upstream oxygen sensor (typically near the exhaust manifold).
• Using a socket wrench with the appropriate size oxygen sensor socket, unscrew and remove the sensor.
• Carefully disconnect the wiring harness connected to the oxygen sensor.

3. Inspect and Replace

• Inspect the old oxygen sensor for signs of wear or damage.
• If the sensor is faulty, install a new oxygen sensor:
  • Apply anti-seize compound to the threads of the new sensor (if recommended).
  • Screw in the new sensor by hand to avoid cross-threading, then tighten it with the wrench to the manufacturer's torque specification (usually around 30 Nm).
• Reconnect the wiring harness to the oxygen sensor.

4. Reconnect Battery and Clear Codes

• Reconnect the vehicle’s battery.
• Use the OBD-II scanner to clear the P0135 code from the vehicle's memory.

5. Test the Vehicle

• Start the engine and allow it to reach operating temperature.
• Monitor the engine for any unusual noises or behaviors and ensure the check engine light remains off.