When you take your car to the shop for just about any problem, the first thing they do is plug a scanner into your onboard diagnostics port and see what error codes are stored in the car's computer memory.

You can buy one of these scanners from Sears or most auto-supply stores for about $130.

What kind of error codes does your car's computer report? Here you go. You will be surprised at how detailed the codes are.

I would like to get one just as peace of mind so I know the guys are not just telling me something to make an easy buck from me. It could be cheap insurance.