I have a 2000 Sable LS Premium wagon with Duratec engine. Replaced top two O2 sensors. In process of replacing two bottom sensors. Managed to remove center sensor but had to pry out after reaching end of threads because it would just turn and not come out of hole. Now can't seem to get new sensor to thread into hole. Any ideas? Also, I can access the bottom right sensor through the wheelwell, but don't have enough clearance to fit a socket or wrench onto the sensor. What am I doing wrong?