I just bought a defi oil pressure gauge and wonder how to install the sensor and still use my factory sensor. I know i would need an adapter to use both sensors. If there is no way to do it other than the adapter then would the sensor fit just in the block. I have googled it and couldnt find anything that was helpfull for integras just Mitsubshi and STIs.

 

It should have a 1/8npt size on the sender. From what I read back in the day is that the factory oil sending unit is that same size 1/8npt. However the threads are slightly different. It can be damaging to those threads in the block if you screw in anything other than the factory oil sensor. That being said I did screw a Autozone brass t-fitting in my block for my sensor and oil feed, my cars been fine so far but I'm getting a sandwich adapter this year.