i was acceleration at WOT and it seemed like it took a little longer to shift than it was suppose to, couldn't really tell, but before it shifted from third to fourth the service light flashed several times and i let off the gas. i floored it again and it didnt flash when it went from third to fourth. Its a 02 A4 Z28, any ideas what it might be?

 

go have the codes pulled, but a flashing SES can be an indicator of a serious misfire

 

Yes, misfire or you hit the rev and cat overtemp limit where it dumps fuel to stop the cats from overheating. Pull the codes as you first step.

 

If it flashes that means its something serious, the only time mine ever flashed was when i had two holes burnt in my vavles from to much of a nitrous dry shot and i th ink it will put the car in limp mode sometimes. I guess its running fine now since you didnt mention anything so thats good. Ju8st take it to autozone and they will scan the pcm for free and you can see if its throwing any codes.