What is an OBD2 scanner ? OBD stands for on-board diagnostics. OBD systems gives you access to the status of the most sub-systems. Will it work with my vehicle ? Most vehicles build after 1996 support OBD2, however you should check your vehicle to be sure. What is the difference between OBD 1 and OBD 2 ? Go here Why should I have this scanner with me ? Well firstly, if you don't know much about cars this device can show you what is wrong with your car. Also you can't always find a mechanic near you when your car suddenly stops or starts making a noise. What is so cool about this ? There is an application called Torque for Android smartphones. You can see what is your car doing in real time. How fault codes will look like ? Couple weeks ago my manager had a problem with his car. He told me it was idling roughly, after scanning the car it turned out the problem was catalytic converter. (And also this application lets you Google fault codes.) Torque pro. Device. Where can I buy this thing ? I bought it from this seller. Also, you can find it in amazon. Pricing. The device costs about $15. Paid application is $5. There is also a free one. After all, I really like using this application. I mostly use it for real-time readings and for my MPG but you can also: Check your engine status. Turn off engine check light. Calculate your MPG. Test your vehicle. Check a car before buying. (Mechanics usually ask for $30-50) Real-time readings. And many more! I'm not sure if Torque pro is available for iOS. I checked from my iPad and it seems like most OBD2 scanner apps are not free and expensive ($20-50).