I haven't replaced spark plugs or have had a tune up on it since I've owned the truck. I've had it since August of last year, but I've kept the oil changed, every 3,000 miles. I've been driving my truck here lately and it acts like it's running out of gas. It'll be at a steady 60 mile/hour roll, and then, just randomly it cuts out like it's gonna die on me. I figured it may be either the spark plugs, or the fuel filter, which neither has been replaced since I've had the truck. Any ideas? know anything about this subject? If so, please help.