ECU temp coolant sensor on 4kq

[Swann, Benjamin R. (BSWANN)]

[ECU temp coolant sensor spec is for 2.5k @ 68F, going LOWER as temp
increases.]

Apparently my sensor is shot as it read ~8k with car slightly warm(while
doing oil change) although it was cold out.  I did not check for warmup
resistance change, but this seemed way out. Yes/No?

Am I correct that ECU thinks the car isn't getting warm.   I have had to set
the FI to run somewhat rich, and I don't hear the Frequency Valve operating
at all even when I lean the FI to the point of the engine about to stall.
Thus I have the car running rich 
just to get it to run right and mileage is lower than normal.  It also does
not seem to develop the power it should, although it sounds great.  The
problem became worse after I installed the 264 cam.

What is the part number for this?

I may be in need of an OXY sensor too, even though I put in a new one a few
years ago.

Anything else that might be contributing for the lambda circuit to not be
functioning correctly?

Regards,

Ben
'85 4Kcsq