Fuel injection system warning light

Hi,

I have a Fiat Punto 1250cc, manufactured 2002.
About 18 months ago the "fuel injection system failure" warning light started to turn itself on and off without warning. Taking the car to the Fiat garage, a lambda sensor was diagnosed as the cause of the problem and replaced. About six months later, the problem started again. A couple of weeks after the warning light started coming on, the car choked completly. Though the car started, the engine shook wildly and responded only slowly to the throttle. Taking the car again to the garage, they diagnosed that the fuel injection computer had broken down, and replaced it at 500 US$.
The problem was solved, but 8 months later (4 months ago), the warning light started coming on AGAIN.

Does anyone have any idea on what is causing this persistant problem?

Thanks,
Noam

Hi,

I've just noticed this post:
http://www.fiatforum.com/punto-techn...hat-wrong.html

I'll try following those instructions.

Thanks,
Noam