Re:Re:Location for aftermarket oil pressure sensor?

It doesn't work for me either, but from the description it's what is commonly known as an oil filter sandwich plate (or adapter) - a quick google search will get you several examples.

It might be easier to fit a sandwich plate on an M-series engine (it sits between the block and the filter and moves the filter away from the block by an inch or so), but it's important to note that the pressure measured at a sandwich plate port MAY be different from that measured at the engine's oil pressure port - the sandwich plate port is on the inlet side of the filter, the oil pressure port in the block is on the outlet side of the filter.

In theory, the pressures will be very similar as the filter will hopefully allow oil to pass freely, but that said, as the filter traps contaminants, the flow will be reduced, the filter should have a bypass valve to allow flow (of unfiltered oil) in the event of the media becoming clogged, should that happen, there WILL be a significant pressure differential across the media & bypass valve.

Taking the pressure reading at the oil pressure port will reveal the reduced pressure, taking the reading at the sandwich plate port will not.

Sorry chaps, the link is working but just veeeeery slow for whatever reason.  Godzilla chewing on the underwater internet cables I suspect.  

Also obv I meant to say "adapter under the oil filter."  Fordem described it in detail.  

Some other fun JDM-style mods on that page (when it does finally load).