+1.. It's happened to me a few times since I've had my car. I go for a drive and it's like "umm.. where'd the power go?" I go home and put some new plugs in it and back to normal. I would start with spark plugs, they are usually an easy, cheap fix.
2000 Gt- Vortech V1 10psi, 4.10 gears, SLP LT headers, Magnaflow cat-back, Eibach pro-sport suspension, MM subframes, 78mm plenum and throttle body, lots of cosmetics, and more