How good is the PFC at reading boost. On my Defi boost gauge (connected at the UIM) I can clearly see it read 10psi as my highest reading but the PFC shows .50 as the peak. Could the PFC be that far off in its reading.

 

sure its not .5 bar??

 

You've been around this long and have never heard of the PFC Commander boost discrepancy? It shows a low value even though it is using the correct P row on the map. Although your difference is much larger than normal.

I suggest you T-into the MAP sensor feed for the boost gauge instead of using the UIM nipple. They should read the same but.... You can read up on Chuck's (cewrx7r1) method of calibrating the PFC boost reading.