I Have a 1996 E320 That had given me code P0170 (fuel trim malfunction Bank 1) I took off the mass air sensor,removed sensor from the body of the sensor,cleaned it with Primis Non Chlorinated Brake parts cleaner(Wal Mart)Dried it with compressed air and reinstalled it with different screws,so I could take it off again easily.The car now runs like a new one.I did this 3 weeks ago and have not had a check engine light since.Car has 78k miles by the way.Just wanted to let everybody know.This place is great,I check in just about every day to learn more..