Oldsmobile/Buick Repair: bucking, buick century, egr valve

Question
I have a 1998 Buick Century, 3.1L V6, with 145000kms on it. I love the car but lately it bucks. First it was at 70kms per hour but now at almost any speed with no strain on the motor. When the bucking starts it gets annoying so i step on the gas and it is perfect, however lately is seens the car hesitates a bit. I changed the feul filter but it didn't make a difference. What do you think is the problem. Some people said it could be a EGR valve, or plug wires, most say they are not quite sure.

Answer
-hi quinton.i would say most definately egr vale.let car cool.not running tap on egr valve.then start eng and tap on valve again..now drive car if any change better or worse egr is prob.but put new spark plkug wires on first to be sure good luck please rate my help  billymac