A narrow band O2 is not even worth installing IMO.

They react too slow, so you really will not know your true A/F ratio at any given point in the RPM range. You would be guessing at best what the A/F ratio would be at a certain RPM.

You can get them to work somewhat OK, but I would never try & tune an engine especially a turbocharged engine.

MBHD


12 port SDS EFI