Audi Q7 engine misfire under load on cylinder 4 and 7, and idle on cylinder 8 despite new plugs, coils, and injectors on Audi Q7

Some Audi Q7 owners report experiencing persistent engine misfires on specific cylinders, particularly cylinders 4, 7, and 8, even after replacing plugs, coils, and injectors. These misfires under load may indicate issues such as faulty fuel injectors, vacuum leaks, or problems with the fuel system, necessitating a thorough check of the fuel injectors and vacuum lines. Additionally, some owners find that a misfire at idle on cylinder 8 could stem from ignition system issues, such as a weak spark or improper timing, requiring inspection of the ignition coil and wiring. Furthermore, conducting a compression test on the affected cylinders and inspecting the ECU for faults are recommended diagnostic steps to uncover potential internal engine issues or electronic malfunctions. Addressing these concerns is crucial for restoring optimal engine performance.