keep getting error codes

23 - maf
24 - iacv solenoid
33 - speed sensor 2

Cars a 1998 wrx, did have a forged engine running a simtek mafless

Fitted standard engine and original ecu back in and re wired maf.

Only difference from standard now is the turbo, was a vf22 but now a tdo4.

car drives great, idles well and boost great in 1 2 3 but if your driving low revs in 4th or 5th and floor it, check light comes and and flags the codes. i can clear codes 23 24 but not 33.

can give it beans in 1 2 3 and its fine, but soon as booted in 4th 5th same again, into limp mode.

does have a dump valve which im removing asap.

got be a bit baffled.