trouble code: PO172.. o2 sensor

[mgate01]

i just got an 02 subi wrx from an auction.. it has some mods, hks turbo 3" turbo back exaust by invedia, (deleted cat) aps intercooler.. its throwing this code PO172.. bank 1 rich condition.

possibilities:

1) faulty fuel press reg.
2)faulty map. sensor
3)o2 sensor

i believe since it doesnt have a cat it probably dont have a o2 sensor either.. is there a "dummy plug" i can get to trick the ecu into thinking all is ok??

also i have been noticing that it pops and crackles on acceloration and there is stumbling and hesitation.. could this be attributed to th prom. at hand as well or something worse??

please help

[SD_GR]

See the following four threads plus any links contained in them:
ClubWRX Forum - Subaru Impreza WRX and STi Community and Forums - Search Results