How do I diagnose and fix a misfiring Vauxhall Astra?

My Vauxhall Astra is misfiring and I'm not sure why. It has been running rough and losing power. How can I troubleshoot and fix this issue?

First, check your spark plugs and replace them if necessary. A misfire is often caused by worn out spark plugs.

Another common cause of a misfiring Vauxhall Astra is a faulty ignition coil. You can test the ignition coils to see if they are functioning properly.

If the spark plugs and ignition coils are both in good condition, the issue could be with the fuel injectors. They may need to be cleaned or replaced.

Lastly, it's important to check the engine compression. A low compression reading could indicate a more serious problem, such as a blown head gasket.