2005 Subaru Impreza WRX Q&A

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

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. -
Answer 1
Any exhaust leaks? Any other mods besides the pshhh valve? -
Comment 1
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 2
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 3
I'd rather have good gas mileage then a dumb pshh sound! haha thanks for the help! -