The ECU thing can be done but if you read it from the upper hose it's much simpler and have a good temp point for a gauge.
And by the way i also have a PSI3 unit and it takes and reads temp from the ECU but it always seems off next to my Defi.

 

im gonna call this place mcd and hope they have it in stock...

 

36mm is the right size. I just installed my 36mm adapter and its' a perfect fit. I measured the upper radiator inlet to be 36mm. 32mm is too small.

 

Do you have OEM upper hose or Samco? I'm thinking you had the Samco hose that is what i have, and if your going to get them you'll need the 32mm.

 

I have the OEM hose. Why would the Samco one be smaller? Does the samco hose stretch to fit onto the upper radiator inlet?

 

hey marksae where did u order your greddy adapter?

 

I got it from evostore.com. It's not on their website, so I just called to place the order. I had to wait like 2-3 weeks for it to arrive. I ordered mine back in late October I think.

 

I ordered 34mm one..on ebay for 24bucks
I couldnt find 36mm..i hope it wont be too small..

 

I have the Greddy adapter and there's a few things I want to add...

1. You will not get an accurate reading until the thermostat opens and the coolant flows through the upper radiator hose. If you want an accurate reading of the actual temp, tap into the thermostat housing.
2. Since the radiator hose is rubber, you will need to run a ground wire off the sensor.

I'll eventually get a tee for the stock and aftermarket sensors but I'll wait until it's time to flush the coolant since there's no reason for me to drain it again now other than to move the sensor.