TRW

My neighbour kindly pointed out that my exhausts are filthy and need a good clean.

He mentioned it might be running rich because of their colour.

Anyone know if this is the case and what is the best cleaner to use?

Shopman

First of all see if you can remove the bolt that fixes them on.
They have a tendency to rust solid so is worth removing and greasing with copperease if you haven't done so already
I replaced mine with greased stainless steel allen bolts.

They are made of stainless steel so clean first with a solvent like WD40 and then polish with metal polish until you can see your face in them Megs or Solvol Autosol are brands that come to mind.

MB

The S (as most cars) do run a bit rich for engine healkth, so sooty pipes is normal. I remember mine were pretty much always sooted up. Evo is the same too.

Best thing to do is clean them off. If it builds up again very quickly there might be an issue.

It would be picked up at MOT time on emissions if there is a problem.

s2konroids

On my car after a week of being cleaned they soot up again.

IIRC they still got shit up but not as quickly with the CAT in.

S runs on the rich side as MB said.