Doctor, something is wrong with my car

When your Check Engine light comes on, instead of taking it to a mechanic, you can try this little gadget out.  When your light comes on, hook this device to your on board computer and let it run diagnostics. Then hook it up to your computer and the included software will tell you what's wrong with your car. Better than that, it will tell you what needs to be done to fix it and how much it should cost.

CarMD Kit $98.99