too rich under boost

[Beems240sx]

ive noticed that under boost i see about 10.2 on my AEM wideband. i know it should be about 11.5 or so. its an s13 sr at 14psi, front mount, isis intake mani, stock injectors, walbro 255. i am however running an s14 sr "WC" ecu, but i doubt that it is my issue. i still have the stock FPR, which i am leaning towards being my culprit and here is why..

i was running 14 psi with the stock fuel pump for about a year, with AFR's at 13.3 under boost. i know some of you will say that is wayyy too lean, but in all honesty i NEVER had a single problem until the fuel pump went on me. so i installed the walbro and it brought me to the 10.2 under boost. from what i have read the stock sr FRP is a rising rate. is this correct? it if it at what point will i be overpowering the stock fpr?

[PyR0NiAk]

The walbro is known for killing the stock fpr (this is in the FAQ) .. id start with getting an adjustable fpr with a gauge..