Hello, thanks for writing in. If you have a misfire (https://www.yourmechanic.com/article/how-can-problems-with-the-ignition-system-cause-misfiring_2) on that cylinder with a new plug and coil then you either have an injector issue or an internal engine problem. Most of the time the problem is internal...
Sure. Either the wheel is out of balance or the tires are just bad tires and they can't be balanced correctly or you've got a front alignment problem. If it's quite new, take it to the dealer to deal with...
