Catalytic Converter??

[Mcheil83]

I have a 2015 Sierra 2500hd 6.0L. I have a rattle in the rear past the 2 catalytic converters and before the muffler. I’m curious if it is a 3rd catalytic converter?? It’s the red circle in the pic.

[newdude]

1 hour ago, Mcheil83 said:

I have a 2015 Sierra 2500hd 6.0L. I have a rattle in the rear past the 2 catalytic converters and before the muffler. I’m curious if it is a 3rd catalytic converter?? It’s the red circle in the pic.

 

 

 

Yes.  2 primaries and one secondary make up the Y pipe.  

[Mcheil83]

Ok thank you very much I appreciate it.  I think I did find the part I’ll have to remove everything an weld this part one

[CamGTP]

Honestly you don't need the 3rd cat unless you live in California, the 3rd cat is not monitored at all and could be removed without issue.