How to fix the engine of my Audi A3?

I noticed that my Audi A3's engine has been making strange noises lately. It also seems to be underperforming. What could be the cause of this issue and how can I fix it myself?

The engine issues could be due to a clogged air filter. It's recommended to check and replace the air filter every 12,000 miles for optimal performance. Consider purchasing a high-quality air filter for your Audi A3.

Another potential cause for engine troubles could be a faulty spark plug. Check for any signs of wear or damage and replace if necessary. It's also important to use the correct spark plug for your specific Audi A3 model.

Have you checked the oil levels in your engine? Low oil levels can cause issues such as abnormal engine noises and decreased performance. Make sure to regularly check and refill your oil as needed.