There are several Auto Parts stores that will check codes for free because they want to sell you parts of course. And of course those parts are cheaper then the dealer, but many parts are WAY cheaper from other sources such as COPs from Ebay or Amazon. A COP from a dealership can be over $100 for one, $45 to $75 from a parts store, and as low as $4 for a better then OEM when bought on Amazon in sets of 8 or 10 (and if you are a Prime Member you can get them in one day). I just bought 10 for less then the price of one from NAPA.
Also the Check Engine Light does not necessarily have to be on for a Code to have been thrown and recorded. It could be missing bad enough to throw a Code but not bad enough to force a Check Engine Soon light. Since you are a woman you have an advantage, so if I were you I would drop by the parts store that offered to check it when they are not busy and they might take the time. Another option is to drop by a Harbor Freight and buy an OBD Code Reader (with a 20% off coupon they are as low as $40) or buy one from Amazon, or if you are a bit more technical buy a OBD BlueTooth Dongle that can talk to a laptop or Android device then install the Torque App.
You can also try to force a Code to cause a Check Engine Soon light by driving in a more aggressive stressful condition such as finding a steep hill and from a standing start at the bottom flooring it until it knocks, let up completely coasting, then floorboard it again. Driving conditions that are more stressful need optimum engine conditions and if a COP isn't up to that, it will most likely at least throw a Code or even cause a Check Engine Soon light. I used the steep hill down by the river late in the evening making it knock but it did not produce a CES light, so when I put the OBD on it when I returned home, I had a P0306 fault registered (Misfire on Cylinder #6).
I had another problem that would not throw a Code to save my life and I was about to shotgun all the COPS and Plugs then the boss called saying he need the COW (Carrier On Wheels) moved. I was driving my truck and didn't feel like going home to get the company truck. The first 4 degree grade I came to pulling the trailer from a 4 way stop caused the Check Engine Soon light to come on. COPs #2 and #5 were bad.
If you drive lots of miles, its a good idea to own an OBD, keep the tools to change COPs and Plugs in the truck along with 2 plugs already gaped and 2 COPS (I keep 4 and 4). Of course I hate limping home but also plan to keep this 2003 EB until either it or I die.
