Question for the more experienced lol

Hi guys (and maybe gals)

I have just bought a "type approved" Klarius 321456 cat off of eBay. This is apparently the one I require according to the online shop (after trying to purchase a £106 version and requiring a cancellation and reorder of the £117 one) yet it seems to be a metallic cat as opposed to the ceramic one I was expecting. I just wondered if anyone knew anything about this?

Also I have a Hoffman racing centre pipe; the straight through jobbie, and now the backbox off a Diesel CDX that I had to buy to repair mine after some twat reversed into my side in a bloody car park. The car has a strange but not unpleasant kinda whistle on acceleration now. There are no leaky exhaust noises (believe me over the last 8 months I know all about them) and it doesn't make that godawful ringing sound with the empty cat it did have. Anyone got any experience with this whistle sound?
I remember noticing that where the flange that bolts to the manifold is welded onto the downpipe they seem to have left a little of the downpipe sticking through. Not much but I wonder if that could be the cause of this kinda whistle noise?


Senior Member
could be the poor assemble at the flange as you say or i have seen/heard some that whistle due to cheap flexi sections.
probably has other poor joins in it which could cause a whistle.
do you have any photo's of it?
Can't find anything that looks like it. It's quite obviously been welded from parts and the cat is a short fat round thing. Looks a lot like those 200 cells you can get. And if you look in the exhaust end of the cat you can actually see quite easily this metal lattice kinda thing going on. I'd say each square is like 1mm squared or sumat. Question is does that whistle noise possibly indicate something I should be concerned about performance wise?
The other thing is I'm not sure if I can hear the whistle noise coming from the back box end lol. Does that make any sense at all?? The dti rear box I pinched had a hole developing just in front of the box so I repaired it with one of those gun gum metal sleeves and putty stuff. It's sealed tight but wonder if anything on the back box might be causing it. I'm clueless lol. Can you tell lol