Short Term Fuel Trim is at -25 at idle... on 2005 Subaru Impreza WRX

I love this car, the only thing is, the motor was rebuilt prior to me purchasing the car.... After the rebuild the car drove amazing, after replacing a hose that goes to the turbo that was broken causing an intake leak. Later, i noticed my car was going through gas like i have never seen, i ran OBD2 Diag. on it.... Short term fuel trim is at -25 at idle!! and also while driving. I did some research and was looking at Blow Off Valves... noticed that the stock was a recirculating BOV. I disconnected the hose that ran from the BOV to the intake system so i could get the "pshhh"... could that be what is causing my fuel problem?? Should i re-connect that hose? Or are there any other ideas on what i should do. I cannot drive the car until it is fixed because the gas mileage is so terrible.

by in Liberty Lake, WA on October 21, 2012
1 answer 3 comments
ANSWER by on October 22, 2012
Any exhaust leaks? Any other mods besides the pshhh valve?
COMMENT by on October 23, 2012
No exhaust leaks, and nope its completely bone stock, hooked that hose back up to the blow off valve noticed by percentages changed ALOT, was -25 STFT not its around -1 to 0.... Seems way better now.
COMMENT by on October 23, 2012
sounds good '0' is the goal , but it's normal for stft to fluctuate LTFT should be steadier and probably is , sorry you don't have your pshhh anymore!
COMMENT by on October 23, 2012
I'd rather have good gas mileage then a dumb pshh sound! haha thanks for the help!