I have an 02 3.0 FF and Yesterday the code came on so today I spent half an hour putting in a new thermostat & coolant temp sensor. The code is still there and the engine temp on the cluster still doesn’t get up to where it should. What should I check to solve the issue before splicing in a new temp sensor harness? I also know it’s not leaking any coolant (just oil & power steering fluid :,) )

 

You can check if the Fan Clutch is bad, always locked
When engine is cold open hood and try to spin the fan, should be hard to turn, cold locked
Start engine and run for 20-30 seconds, shut it off
Try to spin fan again, should be easy to spin, unlocked

In colder weather a fan that's Locked can over cool the engine
Fan clutch is controlled by radiator temp not engine temp, it has a bi-metal spring on the front that is heated up by hot coolant circulating in the radiator, so until radiator heats up fan should stay unlocked

Yes, temp gauge should show just below 1/2 after 5 to 8 min of driving, depends on outside temp

 

Did you clear it and it reappeared? Or did you get a code, change a part, and the code is still there?