Install the sensor to the specified torque.
If the sensor is dropped by mistake, check if there is no problem.
Do not use a cleaner, spray or grease on the sensing element and connector because they could cause a malfunction of sensor.
The sensor or the wiring can be damaged by being contacted to the exhaust system (Exhaust manifold, Catalytic converter etc.)
Install the sensor in the reverse order of removal.
Lambda sensor :
40.2 ~ 59.8 N.m (4.1 ~ 6.1 kgf.m, 29.7 ~ 44.1 lb-ft)