Flyin' Miata Downpipe O2 Bungs
 

Hi all. Done some investigating/reading, but haven't found explicit confirmation.

The FM downpipe has two O2 sensor bungs. The FM turbo instructions indicate that the installer is to put the OEM/narrowband O2 sensor in the upper bung, and the wideband O2 sensor in the lower bung. I'm assuming this is done because the Voodoo or Hydra want it.

If a person is using Megasquirt for engine management, would I be correct in my assumption that the WBO2 still goes in the lower bung, and the upper one should just be plugged?

TIA.

<p>yes</p>

It doesn't really matter all that much.

The common thinking when dealing with wideband O2 sensors is that they like to be placed a little further downstream than is customary for narrowband sensors, simply because they are somewhat more sensitive to heat. This holds true regardless of the ECU being connected to.