Has anyone purchased an OBD code reader for their car? I know there are a host of corded ones at the car parts places. Also, I saw there are bluetooth models that interface with your cell phone with an app. Since my cars are getting to "a certain age" and they like to let me know that the "Check Engine" light is capable of staying illuminated, I was wondering it is worth buying one? I hate running to the parts stores. I do understand that the OTC units do not take the place of the bzillion dollar units the extortionists have.

Any and all ideas are appreciated.