Originally Posted by zetecdan

Install the sensor downstream from the turbo before the catalytic converter. The high exhaust pressure before the turbo interferes with the lambda measurement and the high exhaust temperatures encountered there can damage the sensor.
Do NOT install the Bung below the 3 o'clock or 9 o'clock position.
Condensation can form in the exhaust pipe and permanently damage the sensor.
6 o’clock is the absolute worst position to mount the sensor.