turbo? Knock sensor? running lean?

[west_side_supra]

ok well ill start off by mentioning what modifications i have done

Shimmed the wastgate 4 washers
lightweight flywheel
Stage 3 clutch
muffler
New spark plugs/wires

Now for the Diagnostic's results
it flashes 5 times then a pause then flashes 2 times

what is happening
if i drive it normal i have no problems

when i drive it hard enough for the turbo to kick in the check engine light will turn on. There are no noises and i dont smell any burning. the exhaust smells fine at least rich. but it does feel like its running lean possibly it feels like theres a low response to throttle like a lag or its holding back from power.

the car drives fine even with the light on. it still is boosting past stock so 10-11psi im lost

what i think it might be
from codes knock sensor? Oxygen sensor? lean sensor?

what you guys think