Does your vehicle have a check engine light on? Is it running rough? If you scanned the vehicle with an OBD2 reader and got the P0301 trouble code then here are some things you can do to solve the problem and get your vehicle running properly again. Spark plugs are the most common culprit, but there are other things that can cause a misfire on cylinder 1.
P0301 is a diagnostic trouble code (DTC) that means you're engine is misfiring on cylinder #1. If you haven't had a tune-up in a long time and it's overdue, then it's possibly being caused by a worn spark plug. However, a vacuum leak or a failed catalytic converter can cause this code to pop up too.