Y-pipe.....Its not the shape You ask WHY is it such a pain in the ***. As much as i hate messing with my y-pipe cuz the passenger side is so lovely to work with....yes, I put my cats back on cuz I was sick of smelling exhaust. I actually like the exhaust tone better with them back on. My cutout open even sounds smoother...and after spending several hours trying to get the stupid nuts to tighten the split washers on the bolt...I finally got em tightened.
I need to know what the best way is to have these bolts tighetened without them spinning. I've probably swapped the y-pipe a dozen times but I need to eliminate the time I'm spending on dealing with spinning bolts. The driver side is easy cuz you can rachet the bottom while you wrench the top to prevent spin. Well, the passenger side is a beast and even tho I run split washers...I still have a hard time with bolts spinning. So whats the best solution...Maybe I should run split washers on both ends or really get crazy and tap weld the bolts in..lol Anyhow...help me out here cuz i swap the y-pipe alot and my only prob is spinning bolts...Arghhh

 

Double lock washers,(one on bolt end and one on the nut end) or as you call them split washers. If you REALLY want them to stay there, double lock washers and red Locktite, thread locker. Single lock washers only keep the nut from spinning. Hope that helps