Yes, I have measures resistance which, generally, but not always confirms failed sensor so I only change that one. Doesn't always work though. Sometimes I have had to replace a sensor which appears good to clear the fault.Yes they are a passive device consisting of a coil of very fine wire, so there is potential for wire breakage.
Have you measured the resistance of a failed sensor? It would be interesting to take a failed one apart.
Tomcat59alan Reluctir rings checked, all teeth there and clean, but that wouldn't explain why new sensors work.... for a while