Galaxy Slugish When Pulling Away

[lamebrain]

My P reg galaxy 2.00Ltr Petrol has been sluggish when pulling away. This doesn't happen all the time but will do it at the worst time eg pulling onto a roundabout or turning right accross trafic at trafic lights. Thought a service might help plugs and HT leads replaced. Fault still apparent. Diagnostics says second oxygen sensor faulty, when my mechanic phoned to price the part he was told my car doesn't have a second oxygen sensor fitted! Any suggestions would be appreciated.

[lamebrain]

I forgot to mention that the car has a slight miss-fire which originally led me to believe it could be an electrical fault. Spoke to the mechanic this morning and he says his diagnostics were getting a reading for a second oxygen sensor although when he looked he couldn't find one! My temp guage also doesn't work, thermostat being replaced shortly, could this have any bearing to the fault? A mate at work has suggested he had similar symptoms and his fault was cleared by replacing the EGR valve. So many possibilities but I don't want to go to a Ford dealer as it whould probably cost me more than the car is worth.

[CAR PARTS EXPRESS]

Might be worth taking the only oxy sensor out (in the front pipe) and giving it a clean...also get an emmisions reading to see how its running