Is there any way of using vagcom to try and diagnose my problem with my golf m4 2003 tdi 150 which has a missing and knocking sound on the engine. My friend has the vagcom software but not sure if he knows how to fully use it. My problem maybe a faulty injector or wiring loom on the vagcom it didnt give any error codes. Is there any tests we can do using the vagcom to try to diagnose or rule out certain things?

Any tips/help appreciated.