a friend who followed my car last night said that the catalyst was smelling - does that mean it's probably knackered? and could it explain the poor fuel economy too?

it's a 1998 'S' Daewoo lanos 1.4 (1350 ish cc)

Are there any other reasons for a smelly cat?

Are there any other reasons for a smelly cat?

something to write a song about mebe :D

My understanding is sometimes they can legitimately stink of rotten eggs due to the brand of fuel you use BUT

How do they know it was the cat smelling? Did it smell of unburned fuel, oil etc? Any of the above could be a cause or result of a bad cat (if it is or isnt who knows). Way to tell is service the car properly so plugs filters etc then go to a mot centre and get them to probe the exhaust gasses and that may give a clue. Failing that call out one of the mobile tuning people they usually have all the kit to test/tune the car if something is astray

If the Cat smells of rotten eggs then it is working, and usually working hard.

Smelly cat, smelly cat, what are they feeding you?????
not the biggest f.r.i.e.n.d.s fan but remembered that one

You mean this odours feline ditty? (http://www.youtube.com/watch?v=XNXIZuIBJKs)

Theeeere we go, hit the nail on the head
Shes quite attractive when all is said and done, i think her character on friends puts me off.
Really hijacked this thread sorry mate, this isnt on is it :)

I believe petrol with a high sulphur content causes the rotten egg smell from a cat.

I believe petrol with a high sulphur content causes the rotten egg smell from a cat.

It does and the cat ends up creating hydrogen sulphide which is very very toxic but a stinky cat would only be making a tiny tiny amount so you are ok

it sounds like [sorry smells like] oxygen sensor to me.