they can but you wont get great results cause of it. The flap door style afm really sucks so if at idle there is lots of duration and overlap the afm door will fluctuate greatly causing a very crappy idle. I have had problems with that on other afm equipped toyotas (3vz-e) once it moves tho it is pretty damn good.
BUT if you got with that kind of cam setup then a standalone is strongly recommended or if you are good enough wiring/tuning wise use a piggyback like smt6 to convert afm to maf
