Why does my exhaust pipe look like this? (After CAT)

Why does my exhaust pipe look like this? (After CAT)

I know its probably done for, but why is it black and shiny, i even see words on it. I guess it rusted out.

Nissan Altima 2010

u/Fsgreachv3 — 13 days ago
▲ 30 r/MechanicAdvice+1 crossposts

Ive tried pb blaster over night, the coter pin is rusted stuck in there.

My impact drill wont make it budge

Toyota celica gts 2000

u/Fsgreachv3 — 1 month ago

These have not been taken out for who knows when. The engine has about 100k miles or less on it.

I have a strong suspicion its burning oil.

u/Fsgreachv3 — 1 month ago