What's the sensor that goes on the back of the water pump housing called? I broke mine while removing the housing and Ii don't know what it is, I can't just leave it broken right? Thanks.

 

It's the ECU's thermosensor. It's important and will have to be replaced.

 

yea you definatly need to replace it or your car will run like it is lim in mode. Basicly it wont really go over 35 or so and have no *****. It is a must

 

If the water thermo sensor fails the ECU sets the water temp at 176 F.....even if the water is really something else, like 32 F or 240 F or you fill in the number.

Most of the time your water temp is, what? 180 degrees or so. Depends where you live. Yes, replace it asap. The above was just some FYI that is in the online, FREE, fsm.