Misfiring engine cylinder? what will it take to fix it? how much will it cost? is it safe to drive?

I'm geting codes for


P0172 Fuel Trim System Rich Bank 1


P0306 Cylinder 6 Misfire Detected


P0406 Exhaust Gas Recirculation Sensor A Circuit High|||It is safe to drive. None of those are serious issues and the first two are common nuisance codes. You don't mention make, model, or year, but in general a tank of either top tier gasoline or any old gasoline with fuel injector cleaner is a good place to start. If the car has a lot of miles a tune-up is in order. In late model cars that is not much more than replacing spark plugs but in slightly older cars it involves replacing the high voltage parts - spark plug wires, distributor cap and rotor.|||its time for you to change your spark plugs