How to troubleshoot a malfunctioning engine in an Audi?

My Audi's engine is making strange noises and the performance seems to be lagging. What could be the cause and how can I fix it?

It is possible that the problem is related to a faulty ignition coil. I would recommend taking your car to a reputable mechanic to have it checked and replaced if necessary.

Have you checked the fuel injectors? If they are clogged or damaged, it could affect the engine's performance. Consider getting them cleaned or replaced.