My 2004 Mini cooper recently stranded me on the side of the road. I rec'd a O2 sensor low voltage fault so I replaced both sensors. Car still would not crank! Finally after hours of searching I decided to try putting fuel in the car that was reading 1/4 tank and the car fired right up. Is this common in this car?

 

This happened to me one week after I took receipt of my car. In my case the fuel pump in the tank was bad and thus giving a false reading. This was a problem that originated from the factory in my case, but maybe something similar is happening to you.

 

When you added gas to the car, was the tank empty or just low...did it take a full tank?
Welcome to nam. Some gen2 (turbo cars) have a similar problem, but it should be unrelated in the earlier cars.

 

yes, it took a full tank of fuel.