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Hello,

A newbie to the forum but not a newbie to Fords...

After owning numerous Transits/connects, I decided it was time to buy a car so opted for a 2010 MK2 Focus, 1.8 Zetec sport with the Duratec HE engine or at least thats whats on the engine cover so presume its that engine, it is a 1.8 though.

The issue I have, and which a couple of mechanics are stumped on when cold it seems to idle fine, however as I drive along the road and the engine gets up to normal operational temps there is an idle flutter between 580rpm and 1200rpm this is when coming off the accelerator or when stopping at a junction and also stationary.

Some times it will run ok with the slight hunting idle and other times it willl idle quite harsh then stall, after that it seems to be difficult to start unless I keep pushing the accelerator pedal and it fires into life, it may do this a few times in the same period then run ok again but still with the hunting idle.

I noticed a P0420 bank 1 code but this shows up only sometimes and no other codes in the system, there was a slight sulfur smell but only a couple of times I have experienced this and not always there.

Hopefully someone more mechanically minded than me or knows the engine inside out can guide me.

Thanks in advance.

Will

My bet for dirty throttle body. See: 1.8 duratech he throttle body calibration (I don't know why my pictures been removed).