OK guys, I just bought the obd-2 datalogging cable and software. I was wondering what I should look for when logging my car. Can someone that has this logger tell me what I should plot on the graph and what settings I should use?

Thanks for the help.

If you're looking to do some fuel tuning, I think it might be a good idea to plot the timing advance, short and long term fuel trims, as well as the O2 readings. You could always do a lot more, but I think it's better to focus on the main tuning points.

Thanks for the reply Jason. I am going to plot, timing advance, rpm, and load. If I post the logs here can you guys tell me what you think?

I plot O2 sensor bank 0 (upstream o2) and ignition advance. That way you can see exactly how and when you go rich/lean and the timing gets pulled back from knock.

Load is really just for setting up your fuel curve and safc.

Fuel trims are for setting your FMU/FPR and adjusting for new injectors.

Also, try out this program:
http://www.roadraceengineering.com/obd/obdtool.zip

Really good resource:
http://autos.groups.yahoo.com/group/DSMtuning/

Fuel trims mean nothing at WOT, because they zero. Timing advance means nothing at partial throttle (ECU controlled, it'll just hover around 40-43* advance when there is 10-13% load). Load % is directly corrollated to timing advance. Watching the interaction between the two coupled with engine RPM and knowledge of what gear you're in gives you an excellent graph to deduce knock or problems with excessive advance due to AFC correction.