One common cause of engine misfires and rough idling is a problem with the ignition system. You might want to start by checking the spark plugs and ignition coils. If the spark plugs are fouled or worn, they could cause misfires. Similarly, a faulty ignition coil could lead to rough idling and misfires.

Another thing to consider is the fuel system. Contaminated fuel or a clogged fuel injector could also cause these symptoms. Check your fuel filter and make sure it’s not clogged, and consider running some fuel injector cleaner through your system to see if that helps.