What should I check if my Audi 80's engine runs roughly?

I recently bought an Audi 80 and noticed that the engine runs a little rough. What are the possible causes for this and what steps should I take to fix it?

First, check the spark plugs and wires. If they are worn or dirty, they can cause rough engine idle. Also, make sure the air filter is clean as a dirty air filter can restrict proper air flow. Next, inspect the fuel injectors and fuel filter. If they are clogged, they can also cause rough engine performance. Finally, it may be a sign of a more serious issue and it's best to take your Audi to a certified mechanic for further diagnosis.

To improve the engine idling, try using higher octane gasoline and adding a fuel injector cleaner to your tank. In addition, make sure the oil and oil filter are changed regularly as old, dirty oil can also cause rough engine performance.