Re: Lambda sensors
I've had this same error 3 times on my 156, but luckily it's still under warranty, so no drama.
first time they just altered the lamda sensor wiring, as apparently there is a known fault with the wiring running too close to the exhaust (I'm sure you can find more detail in another thread somewhere if you do a search for motor control system failure)
second time, 6 months later they replaced the Lamda sensor.
Third time they replaced "the other Lamda Sensor" - according to the dealer there is a pre and post sensor.
so far so good, but still waiting to see if its fixed for good.
(Incidentally, replacing the Lamda sensor first time round made a big difference to the MPG figures reported by the computer - was only averaging about 27mpg before, now it's around 32 for the same sort of travelling, and as high as 36mpg on long runs)