After a run my exhaust smells like somethings died in a eggy kinda of way Ive got a magnex backbox on a my99, but both cats are still in. Has I guess the centre cat got contaminated? Or is it normal for them to pong like this. More importantly if a cat has failed, will it strangle the power even more than it does when working correctly?

 

usually caused by sulphur in petrol - supposed to have less of it now though ?

 

Cats stink they always have, its a foul smell, hate being stuck in traffic behind a car with cats in yuk

 

well I only ever use using optimax, so i dont think its the fuel.

 

Cats stunk with the older, sulphury fuel, until they were warm. But as already pointed out, that shouldn't happen any more!

Big exhaust? Hamster moved in?

 

nom exactly, no zorst is standard apart from backbox. So I reckon something is up wit 1 of the cats Warranty item to be fixed then

 

...except the cats aren't the thing that make the smell, it's simply the suplphur that used to be in the fuel. So even if the cats were working, there shouldn't be a sulphury smell.
So, barking/tree/wrong, I think.
Has it done this for more than one tank? If not, I'd run the tank as low as poss & then use a different fuel, or at least from a different station - just to check that isn't it.
To check the cats, just go to an MOT testing station.

 

yeh its always done it with optimax from the same shell station, so I'll try another, thx for your comments.

 

some kid stuffed sommat up the back pipe? only a lay suggestion
try fishing/torching

 

Just pop an air freshener in the BB

 

Just junk the cats altogether

 

I would check inside the exhaust to see if there are a couple of cats climbed inside

 

lol thx for the dead animal in pipe comments

Jake I would love to, but MOT hassles give me doubts. I might do SS downpipe though, as I hear it will still pass with centre cat in.

Its weird thou I gave it a long hard blast last night, and there was no smell at all.

 

are you sure you hadn't just dropped one
beans for tea last night and all that.