[lev16gt]

Originally Posted by Showdown

Why do you want it only powered when the fuel pump is running? The sensor needs to be heated in order to operate properly and powering it with the car on allows for that.

FWIW, Here’s the wiring I had with ms2, the o2 sensor is powered from a fuse panel that powered all the efi when the car is on.

https://www.dropbox.com/scl/fi/vx8hdsgr86ypmp3z6vrhi/EFI-Wiring.pdf?rlkey=j3yhdebhvwm387jron5zdfoxc&st=rjfkhvnc&dl=0

That was my plan on wiring as well, as I have a fuse panel powering the ECU and injectors, until I noticed the install instructions indicate the o2 sensor should only be powered with the engine running. So I dove in and did some research and found it is indeed the suggested installation method to power it only with the engine running. And powering it with ignition on is said to be the leading cause of premature sensor failure (cold engine emitting cold moisture on an already hot sensor and causing thermal shock), as detailed in the following article. It's also specifically stated in the install instructions with the wideband controller to install so it's only powered on with the engine running.

https://www.nzefi.com/bosch-lsu-wide-band-airfuel-ratio-lambda-sensors-fail-often-aftermarket-performance-applications/