I have an 02 Monte Carlo SS and I started noticing a few months ago that when I'm accelerating it shutters a little or stumbles. Usually between 45mph - 60mph. Any ideas on why and which sensor I should replace? I had the TPS sensor replaced last summer but only because I had a mechanic friend with an extra one just laying around and he replaced my plugs and wires so we figured why not. Although i'm sure if it wasn't broke I probably shouldn't have fixed it lol. Any advice is appreciated