P00BC Code Help

I have CEL on and I pulled the code with my SCT X4. The code came back as P00BC, Mass or Volume Air Flow A Circuit Range/Performance - Air Flow Too Low. What causes this? Could it be a MAF sensor problem? I have a new OEM air filter and also bought an OEM MAP sensor and it hasn't helped. The truck is completely stock except the tune that comes with the SCT X4. I did return everything back to stock and I still have it. The truck starts and runs fine. Help!