Overfueling issues

[RS4ABM]

Hi all, Just looking for a little advice. The RS seems to be giving signs of overfueling, seriously coked exhaust tips, black smoke at full throttle, smells of fuel when idling and decreasing MPG.

Now a carbon clean is going to be carried out soon but I wondered if anyone has or has had this issue and what was it related to?


Thanks in advance

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Could be a duff sensor like the O2 one.
If its reading wrong then it'll mess up the fuelling.
Get Vag Com on it an see what it's reading.
Always worth resetting the fuel trims by clearing codes too.

[RS4ABM]

Ok brill, ill get a Vagcom on it.

Recently it did throw up the engine light and the code was PO421 on a standard OBD scanner (something regarding warm up catalyst)?

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Yup - that code could be caused by a bad o2 sensor