hey guys, its been a while since i posted on here. i've been noticing a problem going on with the car... usually i can diagnose it myself but i havent got a chance to get it to school this week (i'm taking automotive classes but i've been on spring break). anyway, i've noticed when you give it 50 - 100 percent throttle going downhill, the rpms will stumble and sometimes the engine will start popping. i'm thinking its a misfiring cylinder and the popping is unburned fuel igniting. yet it doesn't do it going uphill, thats what i don't understand. any suggestions?