my honda accord v6 1998 hesitates someimtes to accelerate after stopping at a light or sometimes randomly loses power and pm's drop as I am driving and I would have to add more gas and press down on the gas pedal a little more for the rpms to jump back up . but once I fill up the tank with 89 grade gas it gives me a smoother ride yet sometimes I can feel it lose power as I am driving . it is in the 280,000 miles range I was wondering what was causing this problem, I keep up with oil changes and maintence the vehicle .