When is a tune-up required on a 2002 infiniti qx4?

A tune-up for a 2002 Infiniti QX4 is typically recommended every 30,000 miles or every two years, whichever comes first. However, it's also important to check the owner's manual for specific maintenance intervals, as factors like driving conditions and habits can affect the need for a tune-up. Signs that a tune-up is needed may include decreased fuel efficiency, rough idling, or difficulty starting the engine. Regular inspections of spark plugs, filters, and fluids can help determine the best time for a tune-up.