I want to purchase a OBD-II scanner but have been overwhelmed with the options availible. Between eBay and google there are way too many to pick from.
I am looking for reasonable bang for the buck, plain and simple. All my cars are GM?s which I believe has VPW protocol and from what I am seeing a code reader is just that, a code reader. All seem to be the same in this aspect, they read the code.
Ultimately I?d like one where I can load each of my cars factory set of parameters and be able to compare my cars true performance against those parameters. I have a laptop and don?t mind using something basic like ELMScan if there are car spec data bases and fairly good software packages to go with it. Can you guys narrow the field for me and guide me to something ok for a backyard mechanic?
Also, It?d be really cool if it were backwards compatible with ODB-I???