How do I fix a faulty turbocharger in my Audi 80?

I recently noticed a loss of power and an unusual whistling noise coming from my Audi 80. After some research, I suspect that my turbocharger may be malfunctioning. How can I confirm the issue and fix it properly?

The first step is to check for any error codes related to the turbocharger in your Audi's diagnostic system. This can be done at a dealership or with a specialized scanner tool. If there are no codes, then it's likely that the issue lies with the turbo itself.