Volvo: 1998 Volvo S70 Chugging, volvo s70 t5, volvo dealership

Question
I have a 1998 Volvo S70 T5 that has a turbo in it.  Whenever I push the gas down all the way the engine and entire vehicle sort of "chugs" and surges until I let up on the gas.  Any idea what this might be?  I thought it might be a fuel filter problem, but someone else suggested that it might be the electronics or something.  Any suggestions?

Answer
I personally like your fuel filter theory best.  It sounds like an engine starved for gas when you press the throttle.  Another thing that occured to me was a timing issue.  Sometimes when timing is advanced or retarded too far, you can get similar issues that get worse as  you press the gas.  In your car, the timing is mostly controlled by the computer, so the idea would be to take it to a Volvo dealership and have them do a quick diagnostic.  Most of the time, that will pinpoint the issue, because the computer has control over almost every system.