If the temp gauge in the instrument panel goes up from normal, then it is the ECT that needs to be "checked". And that is not anywhere near the knock sensors. An error code would have been generated if the ECT were unplugged. The ECT is on the passenger side, behind the power steering pump and under the thermostat housing. It can be checked with a multi meter do determine the Ohms by temperature.

What could be at fault is a relay for the fan. Check for loose wires under the fan shroud. An errant elbow could have nudged it out of the way. Especially if the fan was removed during the knock sensor replacement.

The 414 can be checked by taking off the grab handle and the cover plate, then starting the car. The little fan should turn quickly. The whole sensor does come out, gently, and can be cleaned with a toothpick, and reinserted. Just make sure the little fan turns before you button it back up.

Klaus