[Q] Help with Magnetic Sensor

Hi.

I just bought a second hand Galaxy Note, it came with Jelly Bean 4.1.2, everything fine.

So when i start using it i found that playing Need For Speed Most Wanted with the phone totally horizontal the car keeps going left.

I manage to google some info before posting here, i found that if i type *#0*# i enter a test menu, in the "Sensor" menu there are accelerometer, proximity, gyro and magnetic sensors, in the graph of the magnetic sensor i see a needle which is working but wrong, specifically 15 degrees more in the X axis, as i can see in the image test, so if i raise the left corner of the phone 15 degrees it points zero.

Explained this i'm assuming the sensor is forking fine, it only needs calibration and that's when the problem comes.

I've read that stock ICS for this phone have an option in settings --> Screen that calibrates that sensor, but from what i know, that option is ONLY in ICS and i'm on Jelly Bean! and i've read that due to the brick bug, i can't wipe in ICS, so in order to use that ICS option (from what i've been reading) i have to go to Gingerbread and then to ICS because a downgrade from Jelly Bean to ICS will be a bootloop (unless i wipe).

Now, can you give me another solution ?? I had a LG Optimus 3D and flashed it for a long time but i'm new with the Samsung device, please tell me there's another solution...

Thanks in advance!