Hi there guys, looking for a little help before I go insane.
I have had my mk4 2.0 duratec he for 2 months now, since buying it I have had a rich condition, not REALLY rich just a little rich. Currently my Fuel efficiency is 23.5 MPG this is mostly city driving, I think this is a far cry from what it should be... MPG has been worked out at the pump, brim to brim, trip computer pretty much agrees.

LTFT is -7.07%
STFT is anywhere between -0% and -6%

When I first got the car the thermostat was stuck open so that was replaced, lambda sensor 1 was a little slow so that was replaced. Never changed a thing.

I have been looking at data on the obd scanner and really can't see anything suspect.

Yesterday I noticed that the plugs for the air shut off / swirl slaps were very tight, I switched these over and the car seems to drive better. In the past I got a sudden surge of power at 4000 RPM (when the flaps opened) but now that surge is gone, I get smooth gain in power (flaps open at 2500 RPM)
Please, could someone tell me if this is right?

Them main thing though, is what could possibly be making my car run so slightly rich and is my MPG poor?

Cheers

Dan