My son has a 2005 VW Polo 1.2 engine code BMD.
It brings up P0172 rich mixture fault code after a few days and puts the engine light on.
It still runs lovely with no misfire or loss of power.
I have fitted another cylinder head with new ex valves and guides as no3 cylinder valve guide was worn badly.
I have also fitted a new cam chain and tensioner.
I have Vag-com diagnostics and can see the fuel trim and block 32 always shows a negative figure (-15% approx)
I have replaced coolant sensor , Map sensor and 02 sensors.
I have also checked inlet manifold vacuum and it reads 17in/hg at idle.
It now starting to do my head in.
Any ideas would be appreciated.
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P0172 rich mixture 2005 Polo
Discuss Engine, Gearbox and Exhaust
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