How do I troubleshoot a misfiring engine in my Audi 80?

I've noticed that my Audi 80's engine has started to misfire, causing a rough idle and decreased performance. I've checked the spark plugs and ignition coils, but they seem to be in good condition. What steps should I take to diagnose and fix this issue?

First, try cleaning the fuel injectors and replacing the fuel filter. These are often overlooked when troubleshooting a misfiring engine. If that doesn't solve the issue, it's possible that there is a problem with the engine's compression. A compression test can help determine if this is the case.

Another possibility is that there is a problem with the air intake system. Check for any clogs or leaks in the air filter, throttle body, or intake manifold. Also, make sure the mass airflow sensor is functioning properly. If necessary, replace any faulty components.