How to troubleshoot a faulty turbocharger in my BMW 1 Series?

I recently noticed a decrease in power and acceleration in my BMW 1 Series, and upon inspection, I suspect that the turbocharger may be faulty. What steps should I take to diagnose and fix this issue?

First thing to check is the turbocharger boost pressure control valve. Make sure it is functioning properly and replace if necessary.

You can also check for any leaks in the intercooler hoses or the intercooler itself. These can cause a drop in boost pressure and affect the performance of your turbocharger.