Sputters on heavy load

[Gordon1987]

as i approach 4k while driving the car starts to sputter and wont let me go any higher. this usually happens on heavy load mostly on wide open throttle.. any thoughts on what this could be. im aiming more towards the throttle position switch but i want to be sure before i buy it.

[jlevie]

The first things that come to mind are a bad WOT switch in the TPS, a fuel delivery problem, bad plugs/wires/distributor, or a bad spot in the resistance trace of the AFM.

[Gordon1987]

Ok thanks.