Mercury Forum - Mercury Enthusiasts Forums

Has anyone had experience with replacing O2 sensors on the Duratec Engine? I replced both top sensors without much difficulty. The bottom sensors are a real pain however. I managed to get the bottom center sensor out but it was very difficult to do. Felt like it
was put in crossthreaded. Now trying to install the new sensor, feels
like the threads are messed up. Is there a special way of starting the
insertion of the new sensor. The second sensor on the right side of the engine can be reached through the wheel, but there is not enough clearance to get a socket on it. Can't fit a regular wrench
in there. Any suggestions? Thanks, Don