quote claymore
removing the resistor, in a way, "amplifies" the signal back to the full signal. and no, the resistors are not wired in parallel, but in a series. Parallel only works if you have one resistor with the exact resistance needed. (in the case and subject we're on)
Ever notice how you first start your engine and rpms are higher than it is when its warm? its "working" harder to get it to operating temps faster.
With the ecu seeing that the temps are not 179-185, it will continue to work (higher rpms) to get it to that temp. In a normal car, you see idle is more quiet and smoother as the car is in operating temps. Oh claymore, regarding your Spoon/Mugen low temp thermostats, please read:
Tech - Thermostat
I've been there and done that. Affects more so with an automatic trans, torque lock-up does not engage until temps are within operating temps. Result with no lock-up=higher cruising rpms on the highway, generating unnecessary heat.
Any questions?
You can also check your helms/service manual. it will show all the systems that are correlated with ECT readings and why the ecu requires so many sensors and inputs.