Wideband Oxygen Sensors on 4.5

[fatjon]

I've got a TechEdge wideband unit which I'm planning to install and noticed yesterday that the current narrow band sensors are unusually small. Every wideband sensor I know of (like the bosch LSU) has big chunky 18mm x 1.5 threads. Has anyone come across this problem before and know of a wideband sensor that will screw in without me having a new sensor boss welded in?

Jon