i went to advance auto parts today, and the guy said that there's no way to check it with their little machine. my car's a 99 jetta mk3. there should be a way to be able to check it. shouldnt there be?
SAI has very little to do with the air filter. It's an emmisions system that activates on cold engine startup. It can be difficult to diagnose. Check under the hoos to see if you hear a small electric motor that sounds like an electric fan when the engine is first started cold? Make sure the A/C & defroster are off.