Hey guys newbie here, just thought I'd chime in on this topic. Had check engine light on for a while now and found out the code po449. After searching awhile I found this forum and bingo. I ordered part#2142149 from Rockauto.com shipped to my door for $22. Got some 5/8 heater hose and clamps and no more CEL Thanks for all the info. Oh yeah my truck is 2006 chevy crew cab Z71.