What could cause a misfire at 4000 RPM?

A misfire at 4000 RPM could be caused by several factors, including ignition system issues such as faulty spark plugs, ignition coils, or wiring. Fuel delivery problems, such as a clogged fuel filter or failing fuel pump, could also lead to insufficient fuel reaching the engine. Additionally, issues with the air intake system, such as a malfunctioning mass airflow sensor or a vacuum leak, can disrupt the air-fuel mixture, resulting in a misfire. Lastly, engine mechanical problems, like low compression or valve issues, might contribute to the misfire at higher RPMs.