How do I diagnose and fix low fuel pressure in an Audi A8?

I have been experiencing engine hesitation and stalling on my Audi A8. I suspect it may be due to low fuel pressure, how can I confirm and resolve this issue?

First, you should use a fuel pressure gauge to measure the pressure at the fuel rail. If it is lower than the recommended range, you may need to replace your fuel pump or fuel filter.

Another possible cause of low fuel pressure is a clogged fuel injector. Try cleaning your fuel injectors or replacing them if necessary.