Hello my friends, i have a w203 2005 , i ran a scan map few days ago and it came w/ these errors i posted in the Title up there. After doing so many researches on here and Google, i still not able to figure out the p2004 and p0172 error codes, some talk about a faulty or dirty MAF others mentioned something about a valve underneath the motor it needs to be changed with a new one, well any help from you guys here would be appreciated. Car is running fine tho but i never leave any error codes unfixed. Thanks.