Hi all,
I'm still having problems with the Fiesta. its a 2004/04, 1.6, I have had the plugs, leads, and coils replaced and the ECU reprogrammed.

Now the cars still misfiring and I have the engine warning light on, its staying on all of the time.

The car when stood seems to be hunting for a tick over speed. drops to <500 revs and nearly stalls and then goes to up over 2500, drops back top 1,000 then to 500 and goes over and over again.

The cars also got a persistant misfire up to 3400 revs then it runs fine.

Im taking it back to Fords tomorrow but a friend has suggested the HEGO sensors likely to be the cause?

oh and it just cuts out if i turn the air-conditioning on!

any advice greatly taken!