Quote from Stu:
All good lambda sensors have an internal heater fitted to ensure the tip is at correct minimum operating temperature at all times.
This should be wired to the fuel pump operating circuit so the current hungry heater circuit is only active when the fuel pump is active for both ease of operation and sensor tip life.
The output from the sensor is then also fitted with a marelli terminal into the ecu multiplug for OE performance and reliability of course.
https://passionford.com/forum/viewtopic.php?t=66761