Got a new header pipe, cat, and O2 sensor. Ordered all volvo brand from eeuro but the header was volvo and the cat was bosal. That's fine, but there was no ring that goes between the cat and the header. I think I need it, no? I called eeuro. They are investigating, but by the end of the day they had not gotten back to me. I've put the header on but am waiting before I put the cat on. It will go together but I'm not sure how good a seal it will be without the ring. Anybody? Thanks.