I am also hearing some noises from the smog pump on my 95 GT after replacing the belt. Before it was a little squeeking that would stop after the engine got warm. Now it sounds like theres something scraping or rubbing on the inside. The noise didn't start when I first put the belt on, it started a few days later. I saw where one guy gutted the smog pump and now his acceleration is not hesitant and reving from idle it sounds great. I'm not sure how true this is but what is the purpose of the smog pump and does it have anything to do with passing or failing emissions?