I just ordered this guage and was wondering if the oil pressure sensor attachment that needs to be purchased is difficult to obtain, or is this something I can pick up at the local auto parts store. Any help would be greatly appreciated.
Poot!:(

Subaru has their own oil gallery adapter that is 1/8BSPT.
you have to remove the plug under the intercooler.
Part #11024AA210 is the adapter.
Part #037018200 is the washer.
Total cost was $10.82. Took 5 days to come in...
Or you can remove the idiot light sensor which is under the alternator. Or you can buy one of those plates that sandwich between the oil filter and block.
If you need and adapter to go from 1/8NPT to 1/8BSPT, Summitt Racing has one for $10.69 Part # ATM2269

I got the Greddy oil block filter, so it's going under the engine. I did this so that I could add a temp gauge later without a hassle. Is there a cylindrical unit that needs to be purchased as well? I was on the defi site and saw that there's a part that you need to buy, but it's a little ambigous.

First we need the thread type of your gauges sending unit or connector. The Greddy looks like it came with separate adapters for most Japanese engines. Do any of them fit? Perhaps you do not require an adapter separately...
If you can screw your gauge into the the Greddy piece with what was provided you should be good.

I haven't received the parts in yet, but I like to be prepared for the install. I guess I'll figure it out when it arrives. Many thanx

they come with really good instructions....