Poor performance on altima coupe

[wndrngkblst]

I have a new 4 cyclinde altima coupe. The performance is erratic. When I take it back to the dealer, they hook it up to the machines, test it, and then say there is nothing wrong. But when I drive it out, it rides like a different car, becomes very responsive and peppy. This lasts for about a week or two and then goes back to hesitating as it accelarates and just not feeling very responsive. Any clues?

[MaximA32]

Sounds like it could be some sort of sensor problem. Maybe a Throttle Position Sensor. If you have the knowledge, I would check that. If you wanted to do this, post up and I can get the voltages for you.