Ok, according to the Haynes manual the 4.6 SOHC location for ECT sensor is the front of the intake manifold. There are two one threaded in on the left and one on the right.
The one on the left is coolant temp sending unit for the dash guage and the one on the right is the coolant temp sensor for the computer.
Check the connector on the Engine coolent temperature sensor [the one on the right {driver's side}] If it seems fine test the sensor. You can do this with an Ohm meter. With the engine cold disconnect the wiring harness connector from the sensor and check the resistance between the two terminals, it should be about 58k ohms or so, then plug in the connector and start the car and let it warm up to operating temp, shut it off and test the resistance again, this time it should read about 2k ohms or so. If not, replace the sensor.