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This is probably a stupid question, but i have started to get some black soot type deposits on the back of my bumper from the exhaust, is it a sign of running too rich or could it be something else?

Cheers
Tom

is your CAT ok?

I have always had this. When Mihnea custom remapped my car we had a long chat and the OEM map runs very rich to allow for poor fuel that some owners would have used. However any boost leak will cause richer running. I recently changed the MAF to TURBO air hose with an increase of 5mpg !!!! As thats all I changed I suspect I have run with a small boost leak for a long time. Big boost leaks cause significant performance drops & black smoke as the ECU cannot adapt to them. Small ones I suspect the car copes with & chucks in extra fuel.

How would i know if the cat has gone?

According to the trip i average around 18-19 mpg around town which is what i manily do, and around 24mpg on a run. There doesnt seem to be any loss of power to (still pulls like <beep>:))

As A said above. Soot means over fuelling, it's basically un-burnt fuel exiting the pipe. Look for an air leak. Perhaps change Lambda probe for a new one?

Can't see how it may be the cat's although happy to be corrected.

Looks like i should maybe check for leaks then.

don't worry I had been reading about CAT function earlier today, still at the front of my mind, it is more likely over fueling, especially since you still have power

RS2 cats are wire mesh. IMHO they do not fail like ceramic cats

Tom give me a call if you want to try my `spare` probe CheeRS Al

I might do that Al...thanks:)

I suggest you get the car checked for fault codes which may point you in the right direction

I think what i will do first is fill up with v-power as the last few fuel top ups have been with esso 97 as the shell garage is a bit of a distance and i have been lazy:(