[mb911]

Propane won't work. Here is the deal. If badly rusted you may have to simply twist the o2 sensor out and this will damage the threads as well. There are new bungs as they are called(threaded portion) avaible from many suppliers pelican may even have them. Then after you get the new bung have someone weld it on after it cools apply the anti-seize that is supplied with the new o2 sensor and tighten down. You also may have luck with and oxy-acetylene torch as this is hotter than a propane torch but I have not had good luck with this method on cats in the past. good luck

Ben
77 911 3.0
75 914-6 2.7