P0174/P0171 System too Lean (Bank 2/Bank1)
I got plenty of advices telling me to clean the MAF sensor, in fact I've used special designed (CRC SPECIFICTLY MADE FOR AIR MASS SENSOR CLEANER) And I even replaced all 4 oxygen sensors under the car, but unfortunately did not give me an happy ending because right after I finished and headed down the road, the car threw out the same: code P0171/P0174 again with my service engine light on.

I wonder if there's a very easy positive way for sure to find out if your mass sensor is totally bad and needs to be replaced.

01 BMW X5 4.4i M62