ecu code 23 on pr3?????what??

ok 2 long blinks 3 short...im positive...i dubble and tripple checked this
but...its not on the code list,
like it says in the title its a pr3 ecu
i was thinking it could be a 43 which is "fuel supply system"....
the car runs fine and it seems to not be puting me in limp mode.
any help??