Ok so I am getting a random misfire. I put a dollar pill on back of exhaust it sucked in every now and then. I replaced coil pack, plugs, plug wires. ran fuel injector cleaner through. Before this the coil pack went bad and only 2 cylinders were firing. Then i replaced the coil pack and all 4 fired. replaced the plugs and wires all at the same time as well. I am stomped.. can someone help me possibly figure out whats goin on? also when at idle if i hit the gas a belt squeals. and when i cut the wheel all the way a belt squeals as well. someone help plz? No engines codes are being set off.