Nit pick to the nit pick for anyone wanting a fuller story ...I know I'm picking a nit, but I feel that it's important to clarify that statement.
The muzzler doesn't manipulate the sensor, it manipulates the signal that the sensor sends. As you know, there is no interaction with the sensor itself and I think that that is a key distinction. The sensor still outputs ("reports") the correct value, the muzzler then attenuates it a little on it's way to the ECU.
Manipulating the signal sounds so much more benign that manipulating the sensor itself.
The ECTs are NTC thermistors. That means they are resistors (BTW, about the simplest, most robust electrical device other than a wire) that have a negative temperature coeficient (NTC) so as they warm up their resistance drops (which is not how things usually work for most materials).
Similarly, this is about the simplest sensor you will ever find anywhere. If it could think, it would be flattered that it was credited with "reporting" the correct value, but sadly it's just a humble temperature-varying resistance in a circuit driven by its boss, the PCM.
Here's that circuit, shown here from the 2011 service manual, for both ECT1 and ECT2.
So the PCM (ECU) provides a regulated 5V to a known, fixed resistor, measuring the voltage on the downstream side of it. That measurement will let it know the current flowing through the complete circuit, which will let it infer the resistance, and therefore the temperature at the ECT.
The current, after flowing through that reference resistor, flows through the variable resistance of the ECT thermistor. As the ECT resistance changes with temperature, the measured voltage on the upstream side of it will change. That voltage measurement is what the PCM actually uses.
The VCM muzzlers (not sure about the newest ones) adjust things by putting an additional resistor in series with the ECT thermistors. Resistances in series add, so it makes the PCM think the ECT's resistance is higher than it really is, which means it thinks things are colder than they really are.