drain bolt on the oil pan seems to be leaking

teflon tape is NOT the fix. teflon tape is used for tapered threads found on pipe. the purpose of teflon is to lubricate the threads to alow them to be tightened down till the tapers ( male and female) mate and form a seal. it allows the threads to tighten without galling. it is not for sealing bolt threads.
if your oil pan bolt is not sealing you can get a new proper bolt for it. if the pan threads are bad you can get an oversize bolt that was designed to cut new threads slightly larger than the orginal.