How do I troubleshoot poor engine performance in my Vauxhall Vivaro?

My Vauxhall Vivaro has been experiencing poor engine performance, causing me to lose power while driving. How can I diagnose and fix this issue?

First, check the air filter and replace if necessary. A clogged air filter can restrict airflow and decrease engine performance.

Another possible cause could be a dirty fuel filter. Have it checked and replaced if needed.

If those solutions don't improve performance, it could be a problem with the spark plugs or ignition system. Have it checked by a mechanic to determine the exact issue.