RepairPal Certified shops can diagnose and repair your 2004 Nissan Altima. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Depends on type of plug, vehicle, miles driven etc. If your plugs are original, it is overdue. 70,000 miles is kind of as high as I would go or 5 years max.
Thanks very much