My girlfriend has an 04 plate StreetKA and we have never had a problem with it!

It has just been recently serviced by Ford and no problems were reported, however, ever since we have had it I have thought the fuel consumption was quite poor even on a run??

Sometimes a journey can use half a tank, whereas other times the same journey may only use a quarter of a tank???

The car also seems to be very sluggish, like its towing something and in my opinion has lost power, the engine has always ran a bit eradic and spluttery as has the exhaust note???

Any ideas??

Any lights up on dash as my ka was using a lot of fuel and running erratic and it was lambda sensor

Turns the first o2 sensor had gone!

Fuel consumption much better now - a big difference but the car is still quite poor in terms of low end acceleration and idle!

It starts fine, yet when it idles it is not smooth at all, spits and pops and the acceleration seems very jerky!

Its just had a major service at Ford and they replaces plugs leads etc......

Any ideas??

Could be the idle control vale.

Also does it rev freely when under load or struggle?

If it struggles it could be a collapsed CAT

I was thinking this? With the o2 sensor being bad for best part of a year and the car running rich could the cat have been damaged??