My 2007 CX-7 has CEL on - again. Last time I paid the local mechanic $70 to hook up computer and tell me the gas cap was loose. Can anyone tell me how to turn the light off for less than $70? Thanks

 

Best is to find out why CEL goes on and fix it. (Recent Mazdas have had a history of gas tank cap issues, usually jamming), and Mazda has replaced the original cap with a modified design; check this out.
To do a CEL reset without using a scanner, leave the door open so the coutesy light is on, then disconnect the negative battery terminal for about 30 seconds; this will clear the CEL, among other things.
Once you have done this, you will have to reset your clock and tuner presets, AND if your entertainment center has an ant-theft provision, you will have to re-enter the code to re-enable it.
You can get this code from a dealer, or you can search this forum for how to do it yourself.