How important is it to run a oem temp sensor? I really wanted to try a temp sensor and got one from a local parts store. It says made in italy. I am noticing my fuel economy is not nearly as awesome as it was before I changed the sensor. Is it possible a leaking oil breather line could create a noticeable fuel economy issue to? Can I try using my temp sensor from my n/a 93 legacy on the 94 legacy turbo? The one I put on the 93 was very recent and OEM. Any input would be great.

I'd recommend using OEM sensors.

 

Yes you can use the OEM sensor from your non-turbo engine. They are the same.