Luago,
There are a lot of OBD-II scanners in the market so you'll have to be specific on what your requirements are, including your price range. Do some research here
http://www.obdii.com/ and post back your detailed requirements.
For example, my requirements were for a simple device that would work on my 97 Cruiser and other friend and family vehicles. This means the device would need a "universal" type of interface and software. Low price (under $200) was a
major requirement. My only technical requirements were that it had to read stored MIL codes and reset them. (They all do this!) I love Palm devices and wanted one that would work with a Palm
and a laptop PC (WinPC.) The Palm capability was a "nice-to-have" but not required. Displaying standard OBD-II signals in real-time was another "nice-to-have" for me.
What this leaves out in the above requirements is a lot!!
For example:
* Toyota specific diagnostics
* Ability to capture, store, and recall stats from many vehicles.
* Touch screen operation (like an auto shop might use)
* General diagnostics with help on how to resolve problems by code.
* Sophisticated user interface and software
* ... and lots more features the pro units have ...
I selected the OBD-II device from Harrison R&D. (
http://www.ghg.net/dharrison/) It met my requirements above but it is a minimalist solution. There are much better units available and I did very little research before selecting their product.
Bottom line is that it works, it's cheap, and it met the specified requirements.
-B-