Sounds like you have an air leak, Check the requested MAF against the actual MAF,
Can't remember what measuring block. 32 seems to ring a bell?
The low MAF reading is most likely unmetered air entering somewhere after the MAF.
Check the pipes under the manifold, The car I was working on kept flagging the same code.
2 of the pipes had completely perished and had holes in.
We also replaced the injector seals, Top and bottom and the inlet manifold gasket.
Solved the issues we were having.
One thing to find out, Is the Bosch MAF from GSF a recon unit or new?
I know the recon units are not that great and can cause issues. We found this out the hard way, however our bosch MAF's came from EuroParts.