I am going to replace my pcv valve and just wanted to make sure before I order. I have an 2004 and it looks like the one where you screw instead of push in. Do I need the grommet? I noticed 2001-2003 (1220450020) have a different pcv part number than 2004-2006 (1220450030). But the grommet is the same part number for both 9048018001. Thanks