Hi can anybody help.... the Engine cuts out after 40mph and says Engine System failure... Ive been told it may be the O2 sensors ... any suggestions...?

Hi Martin
How do you mean it cuts out, - Does it go into limp home- shut the power down- and put the warning light on (EML)
Or you mean the engine just dies out and stops - leaving the ignition lights on the dash and the car free wheels to a stop.? You don't stop playing because you get old, You get old because you stop playing.

07 TDV6 been and gone. 08 TDV6 been and gone. 08.5 TDV8 in evaluation mode and now gone. BMW 535D M sport Been and gone, Now time for RRS No4 - TDV6 HSE in Stornaway with Ebony - 09 Model 6 months old.
RS Cosworth 4x4 Stage 2 Mint for summer
Audi TT
Astra VXR for the daughter.

the engine goes into limp mode... ie: there is no more revs.. any clues anybody...?

There is loads of things it could be
Need to take a trip to dealers so they can drive it with the diag kit on and pin point it for you

Good luck You don't stop playing because you get old, You get old because you stop playing.

07 TDV6 been and gone. 08 TDV6 been and gone. 08.5 TDV8 in evaluation mode and now gone. BMW 535D M sport Been and gone, Now time for RRS No4 - TDV6 HSE in Stornaway with Ebony - 09 Model 6 months old.
RS Cosworth 4x4 Stage 2 Mint for summer
Audi TT
Astra VXR for the daughter.

Sounds more serious than an oxygen sensor. Usually that only causes the Check Engine light to turn on and no limp mode, kinda like when you don't screw the fuel cap all the way... Sorry to hear about your trouble, keep us posted.