FYI, the programs with a datalogging function that I've successfully used with the ELM 323 scan tool:
-
wOBD v1.40 - http://www.obd2crazy.com/wOBDv140/index.html
This is the one I used to capture the data posted yesterday. Not particularly user friendly, but did the job. It's a small program, p120/w98 friendly.
-
Digimoto Lite -
http://www.digimoto.com/updates.htm
Requires the MS .Net programming framework to be installed. Resource intensive. It works on my p120/w98, but it loads & runs slowly. More user friendly than wOBD though.