post it if you cant find the responce there is a guy who goes by the screen name Tech he is very informative & can answer your questions sorry for such a later responce I have been away from my computer for quit a while

I am new to this, but wanted to reach out to someone, is there a way to reach everyone? I have a 06 S40 w/ Engine Light on, code is PO172 which I know is showing running rich. I have changed the up stream O2 sensor & cleaned the MAS sensor as I found it dirty. Car has 72k on it. Pulled the air filter, did not look that bad, for some reason, I don't think it is getting enough air. Any ideas on how to correct it?