I'm tired of auto mechanics charging me 50-75 dollars just to connect to my auto's computer and tell me what is wrong then sometimes replacing parts that don't need to be. I can go down to our local auto parts store and have them plug in for free, hoping we will buy parts from them. It's a racket, if you ask me!
With this inexpensive tool, you can check your vehicle when an error light turns on and find out exactly what is the matter with the car. Often you can just reset the error and see if it comes back. You can take your vehicle to the mechanic and share the information with him, saving you the cost of diagnosis. It really helps if you know what you are talking about.
This OBDII reader will talk to the computers and sensors in most modern autos. You plug the device into your onboard computer and follow instructions in book (included). It couldn't be simpler. You really need this device in your toolkit, it will pay for itself the first time it's used.