Though there are a lot of threads about check engine light, code readers and "what does this code mean," I was very surprised to not find any search results for the ELM327 code reader or Torque Android software. It is super inexpensive and gets extremely positive reviews. Used in conjunction with Torque software for Android phones you can net out at less than $20 for a code reader. I have never owned a code reader but from what users say this does everything a $200 reader will do and more.
I found this review to be very informative:
http://www.youtube.com/watch?v=8w37I...eature=related
I order my ELM327 today from this source. This is for version 1.5, the newest version:
http://www.ebay.com/itm/310369090122?ssPageName=STRK:MEWNX:IT&_trksid=p398 4.m1497.l2649
Here is the Torque software. Be sure to read User Reviews. There is also a free version which is what I plan to start out with:
https://play.google.com/store/apps/details?id=org.prowl.torque&feature=search_result# ?t=W251bGwsMSwxLDEsIm9yZy5wcm93bC50b3JxdWUiXQ..
This combination is cheap enough anyone who owns an Android phone can keep one around for an emergency. I just bought my first Android phone (LG Optimus Q) a week ago and am having a ball with it! The uses seem almost endless.