I'm looking at Rock Auto for mufflers for my 2005 Legacy 2.5i Limited (non turbo 2.5). They list one as "w/U5" and the other "w/o U5". I can't figure out what U5 means. I can see a difference in the catalytic converters up front, but the rear half looks the same.
The only resonator pipe they sell is made by Walker and seems to be universal.
http://www.rockauto.com/catalog/moreinfo.php?pk=3847608&cc=1430732
The only mufflers are Bosal and that's where I find the U5 reference.
http://www.rockauto.com/catalog/moreinfo.php?pk=3483600&cc=1430732
Any ideas?
