O2 sensor
 

I have plans to test my O2 sensor as soon as the weather moderates. According to Clark's garage, the best way is to introduce propane to enrich the exhaust mixture to get readings with a V-O-M. I don't have easy access to propane, but I do have MAPP gas ...I certainly don't want to use it if it's too strong of a gas
My question is, has anyone used this method? Sensors run $60-200 and I don't want to swap it out if unnecessary. I have read that they should be changed every 30k miles at any rate, tested or not.

Yes, MAPP gas will work just fine.

There are a couple of youtube videos on doing the test.

a failing O2 sensor can present as wandering warm idle or poor MPG.
do you have either of those symptoms?

if so the easiest test is, unplug the sensor and see what changes.

alternatively, has the sensor been changed since youve owned the car, or in the last say 5 years?
if not, just replace it.
944 o2 sensors (if you're not in a super-salt-rust area) take 5 mins or less to swap out, some cars you don't even have to jack the car up first.

Idle will surge a bit, but my mileage is about 15-16 around town, not much better than my Dodge Ram. I put in new plugs, wires, rotor bug....I've done quite a bit since June to get it back up and running. I'll probably just go ahead and change it once weather permits. I can get a Bosch for 60 and I do have an O'reilly gift card to use :)

I have not used the heating method, only the raise it out of the stream method.