need help on a spit and sputter problem
 

i have a 98 gt. in between 3000rpm-3500rpm it spits and sputers but after 3500 it pulls great. and before 3000 it pulls great. it only does it under a load. i dont have a clue. if any one has any advice please help.

Codes, any errors thats the best start. How many miles do you have on it.

checked codes
 

i took the car to the local ford dealer and a buddy of mine put there computer on it and nothing came up. it has 99,000+ miles

TPS sensor could have a dead spot on it. Have you done
a basic tuneup like fuel filter, spark plugs, wires For that many miles this is a must.

Id say fuel filter.

i have new autolight plugs and msd wires, but i have not changed or cheked the tps