missing a little under hard acceleration

my 95 ssei bonneville has been missing during hard acceleration.. has new plugs, wires, fuel filter, air filter. no codes on scanner. the car has 134k miles on it and has never had the coil packs changed.. could it be the coil packs? i cleaned them and noticed the metal blade had a yellowish color to it. thanks for any help. vernon the miss is not real bad but is noticeable.

Welcome to AF, low fuel pressure, a partially clogged injector/s , cracked plug insulator are just some of the possibilities, a full scan should be done to look at misfire counts.

In addition, you could have a clogged catalytic converter (cat) which is not uncommon for the miles you have if it has never been changed or removed.