How can I fix a sluggish engine in my Audi 80?

My Audi 80's engine seems to be running very slowly, making it difficult to accelerate and causing a decrease in fuel efficiency. I've tried changing the oil and filters, but it hasn't made a difference. What could be causing this issue and how can I fix it?

It's possible that your spark plugs may be worn out or dirty, causing a decrease in engine performance. I recommend replacing them to see if it improves.

Another common cause of a sluggish engine is a clogged air filter. Make sure to check and replace it if necessary.

If neither of those solutions work, there may be an issue with your fuel injectors. Consider taking your car to a mechanic for a professional diagnosis.