[f5fstop]

part of an emergency kit should also include a large pair of pliers to pull a large nail out of a tire.
as for the sensor, yes, fix-a-flat will destroy them as others here have said. however, if out in the middle of nowhere, and it is a true emergency, use it. a new sensor is only about $50-75.00. i carry a truck size can of fix-a-flat, as well as plugs, pliers, and a compressor.