Where is the oxygen sensor located on the old Passat?

[OEmma]

The oxygen sensor on the old Passat is located on the exhaust manifold, with one in front of the catalytic converter and another behind it. The front oxygen sensor detects the oxygen content in the exhaust, allowing it to send signals to the ECU, which then adjusts the air-fuel ratio. The exterior changes in the old Passat are mainly reflected in minor details: chrome decorations on the side windows and body-side rubbing strips were omitted, the glass is standard, door handles are unpainted, and the wheel size is reduced. Inside, leather seats remain standard, with manual adjustment for the front seats, and the rear seat center armrest was omitted.