Problem with 97 Mercury Villager?

It'll run fine the first few miles then it hesitates extremely bad and rocks and makes noises after that. it feels like how a lawn mower sputters as its running out of gas. We've replaced the TPS and fuel filter and made sure it wasn't the catalytic converters. Its not showing a check engine light. Anyone else ever go through this and might know what it could be? Thanks in advance.