Help my jetta runs but lacks top end

i just did a tune up on my 95 jetta 2.0 new plugs wires cap and rotor and it still sputters when you have your foot steady on the gas peddle when you give it gas it feels like some one is holding it back when you get up around 3500 rpms to adout 5000 rpm there is no check engine light on im lost i need help also it seems to have slite lope at idle

Fuel filter or catalytic conveter clogged?