Lambda Sensor Issue?

[darkhorse1210]

Just back from a near 400 mile round trip in the RS2. As always the car was absolutely rock solid and made light work of the crappy conditions we drove through.

However, the friendly on board computer gave me and avg MPG for the trip of 19.8.

Now granted, we weren't in the slow lane the whole way but 90% of this journey was motorway miles.

Now I'm sure I've asked this question before but isn't this MPG more typical of booting it round A roads rather than motorway cruising? If so it is likely that my lambda sensor has carked it and it making the engine run too rich?? The cost of the lambda sensor would be covered quite quickly if I could get the engine running on less fuel!

All thoughts welcomed. Tom