Well with a '93 you need no scanner...just use this procedure and the codes read from the CEL.
www.avigex.ca/xport/readingcodes.jpg
Agin once started the cam sensor is not really a critical component. I'd rather suspect the crank sensor....not to funny to change.
Unless you have positive indication of poor gaz mileage or other codes, the oxygen sensor ...given the place where it is...is not to be changed just for fun.
ANd using the procedure above, you can use it with engine running (field service mode) and see when the computer changes from open loop to closed loop operation....and if the trouble starts showing at that moment, then indeed some suspicion of the O2 sensor can be thought of.