The vehicle had a persistent misfire on cylinder 1, with the engine management light flashing under load at around 2500rpm.

The misfire was isolated to cylinder 1 only, with fault code P0301 consistently returning after clearing. Despite multiple ignition and fuel component swaps between cylinders, the fault did not transfer, confirming it was not caused by coils, plugs, or injectors. Mechanical checks initially appeared normal, with compression testing showing even readings across all cylinders.