I installed the Slp lm1 on my 01 z/28 and it was having this issue where it rattles when starting off but not at idle and it has come to a point where it only does it sometimes. I thought it was the tips because they were stainless steel camaro tips that I bought separately and were clamped on, I got those welded and it seemed to make it less but it still happens. When I got my pinion seal fixed he said the rattling could be cause by it vibrating the firewall. Anyone know why its happening? I'm planning on getting longtubes so I'll probably see if I can tighten it while installing them. So please if you know anything I'd be happy to know .

 

i'm having an identical problem right now with my new y pipe, happens when starting off but not idle, i had mine welded on as well and it isn't touching anything, it might be the new clamps/pipes adjusting or mybe need tightening