P0125 code
 

I have a 2001 Montero XLS 3.5 with 220,000 miles on it and it's throwing a P0125 code. I've put a new thermostat in it, changed the coolant, bled the system. Changed the ECT sensor, put a new end on the plug to the sensor and looked over the wires to the sensor and don't see any obvious problems. I clear the code and it pops within the first 5-7 miles of driving. Any thoughts?