95 jetta stumbles going down the road

i have a 95 jetta stick shift that has about 96000 miles on it when you are out on the road driving with your foot steady on the gas at about 40 mph the car stumbles and if you step on the gas it has no real power up top runs good around 200 rpm to about 3500rpm then it feels like some one is choching it please help thanks merick

it also has a slit miss at ideal please help merick

Check the engine for any worn vacuum lines and listen for air leaks.
Also check the spark plugs and the leads,to test the leads run the engine- remove each lead with non-conductive pliers to avoid a shock,the engine idle should get worse with each lead being pulled off, if it doesn't you know the leads are worn.
Could be a number of things-does the vehicle smoke?is the car serviced regulary?

it does not smoke and i checked all the vacum lines they look good when you drive it feels like a pulsing and misses at idle colud it be an o2 sencer and were is it on that car thanks for the help