Question: I have a 2006 Kia Sedona, and it randomly misfires roughly once for every week of normal driving and once after each carwash. When it happens, I pull over and shut off the car. Then, I turn ...

Most spark plugs come from the factory with a pre-set plug gap that is recommended for the application. Experimenting with wider or tighter gaps is one way to dial in your engine’s performance, but ...