I have got the driver's side replaced but the passenger side seems to alot harder. I rented a O2 sensor socket from Auto Zone and I cannot seem to get enough leverage to break it. Has anybody done this and know any tricks to get it out?? This is on a 1995 Formula Firehawk
Thanks

 

I used a long extension and a swivel and went from the bottom. It takes some time, but you'll get it. I had to warm the pipes for about 2 minutes. It made it easier.

 

I tried socket and open end wrench and multiple variations of one/two ramps and couldn't get it to budge. brought it to local shop and was informed it wasn't me. had to drop pipe, torch sensor for removal and weld bung. car had 108,XXX mis on it when replacement occurred. although the sensor is pre oiled with antiseize the piece will seize in bung after prolonged intervals. cost $100.00 for replacement after about 4 to 5 hours of my attempts.