Step 1: Cold engine + clear top access
Work on a cold engine. Open the bonnet and pull off the plastic engine cover — that's all the access you need to reach the sensor from the top.
Difficulty
Intermediate
Est. time
30- 35 min
Tools
Extra-Long Oxygen Sensor Socket 22mm 1/2"Sq Drive
Parts listed
4
Fuel
Petrol
Engine
1984cc
Year
2018
Platform
Volkswagen Tiguan
Procedure
Step 2: Locate Bank 1 Sensor 1
The upstream sensor screws into the exhaust manifold, before the cat. On this car it's exposed and easy to see once the cover is off.
Step 3: Disconnect the connector
Trace the sensor lead to its plug, press the tab and unclip it. Keep the harness clear of hot surfaces.
Step 4: Remove the old sensor
Fit the slotted 22 mm O2 socket over the sensor (the slot lets the cable pass) and turn counter-clockwise. It came off without penetrant here; on higher-mileage or rustier cars, spray penetrant and wait ~5 min first.
Step 5: Fit the new Bosch sensor
Anti-seize on threads only (never the tip). Hand-start, then torque to ~45–50 Nm. Reconnect the plug; refit the plastic engine cover.
Step 6: Clear codes & verify
Clear P0135 and drive until readiness completes. Confirm the heater code stays away and fuel trims are within ±10%.
Parts & materials
- 22 mm sloratchet + extension×1
- Bosch Lambda Sensor (Before Catalytic Converter)(0 258 027 215 (LS 27215))×1
- Gloves×1
- Penetrant spray×1
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