But they will just tell you what the code says, which may or may not be the solution. I took my van there (the light comes on every year in the winter for 5 years now) and they told me it was a bad thermostat sensor(?). I had a friend who would have replaced it for free, minus the part and beer charge.
However, when I took it to a mechanic (with a business) I know for a second opinion from Autozone, they said that the code could mean that or a whole other host of issues. He took it to a catalytic converter guy who said that it could be that, or a computer issue that the dealer could re-set (as only the dealers have the ability to do that) and it would turn the light off, but he could find nothing wrong with the van.
All of this was no charge - good to live in a small town and either drink or be related to a lot of people. Now, I get my oil changed and tires through him, so I guess it's not free.
When I called the Dodge dealership, there was the immediate fee to hook it up plus the labor charge. I said no thanks.
I was told that if it is running and not smoking, smelling, or banging, then keep driving it. If the performance changes noticeably - gas mileage, gear shifting, acceleration, etc., then that with the check engine light indicates a problem. It has served me well for several years now. It will be 10 years old with 200,000 miles.