Just to update and summarize for anyone that skips to the later part of this thread.
As I mentioned, everyone NEEDS to buy an OBDII tool. For as little as $30 you can have a tool that does everything you need. Actually the cheaper tools have capabilities to record data to a CSV file so the data can be graphed as needed. See some of the graphs below.
How do you get a tool for $30 or under.
If you have an Andriod phone or tablet, a $5 App and a $15 interface.
If you have an iPhone, iPad or iTouch, a $10 App and a $25 interface.
If you have a Windows laptop you can get ODBWiz with interface for under $30. From Amazon, link at the beginning of the thread.
Also ELM has their own software provided with some of their OBD interfaces called ScanMaster ELM.
Some other low cost options -
$33 - http://www.amazon.com/Autel-AULMS310...=pd_sbs_auto_3
$43 - http://www.amazon.com/Autel-MaxiScan...sim_sbs_auto_4
I have not used these specific tools, but it looks like they offer most features that are needed.
And you can get a very good stand alone OBDII scan tool for just under $100, or step up a bit and likely get a very good tool for around $160.
Search Launch CReader 123 or CRP123/129 and see what these can do for over 30 different manufacturers for between $100-$200.