how much does it cost to turn of maint req light

have the codes read for free....then take it from there,,,,

No cost. Turn the key 'on' and make sure the odometer is on total mileage, not TRIP 'A' or 'B' Turn key off. Press the button and hold it down. Turn key ON, or RUN position (do not start engine) and hold the button down and you can watch it count to 4 lines, 3, 2, 1 0. Release the button. The light will be off.

Don't confuse the text 'maintenance required' on the right side of instrument cluster and the CEL, the icon of an engine in the left side in yellow. The 'maint req' is triggered by mileage and running time, and is just an oil-change reminder, and does throw codes.