how to fix the P0135 code in my Volkswagen Golf MK7.5 (2020-Present)?

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to avoid any electrical shorts.

2. Inspect and Repair Wiring

• Tools Required: Wire strippers, electrical tape, heat shrink tubing, multimeter
• Inspect the wiring harness leading to the upstream oxygen sensor. Look for any signs of wear or damage.
• If damage is found, cut out the damaged section and splice in new wiring using wire connectors.
• Secure the repair with electrical tape or heat shrink tubing to prevent moisture ingress.

3. Replace Upstream Oxygen Sensor

• Tools Required: O2 sensor socket, ratchet, torque wrench
• Locate the upstream oxygen sensor, which is typically found in the exhaust manifold or upstream of the catalytic converter.
• Use the O2 sensor socket to remove the old sensor by turning it counterclockwise.
• Apply anti-seize compound to the threads of the new oxygen sensor.
• Install the new sensor by threading it in and tightening it to the manufacturer's specified torque (typically around 30-40 ft-lbs).

4. Reconnect Electrical Connections

• Reconnect the wiring harness to the new oxygen sensor, ensuring a secure fit.
• Reconnect the battery terminals.

5. Clear Error Codes

• Use the OBD-II scanner to erase the P0135 code from the ECM.
• Start the engine and let it idle for a few minutes to allow the sensor to heat up.