Thread: Running too rich?

My check engine light came on during my drive to work so I plugged in my Bluetooth scanner on my way and got a P0172 (System Too Rich Bank 1)
OBD-II Trouble Code: P0172 System Too Rich (Bank 1)

My fuel trims are all out of wack im getting -12.5 to -19.5 LTFT and +10 to -10 STFT. I cleaned my MAF and check vac lines. I thought mabye the
180 stat was causing it but I replaced it with my 195 with almost no difference in fuel trims and its still happening. I searched for someone having
a similar problem but almost nothing came up for the code on GP's. Car details in sig. Im stumped here guys. Any ideas?

Did you use a guage when you checked your vacuum?

exhaust leaks can also fool the PCM making it think the motor is running lean

yeah scanner and my gauge pod to monitor vac everything is normal 20 in Hg idle and 8psi of boost. Could bad gas cause the car to run rich? if there was water in it you would think it would be running lean and adding fuel to compensate not cutting fuel?

Got different gas still getting bad LTFT's Short trims look better getting 7 to -7 STFT's. I should also mention that I have no misfires.

Im still struggling with this, Im thinking about replacing bank 1 o2 sensor. Sensor seems to be working fine but im out of ideas. Overkill pcm will be here today and I have the bank 2 (after cat o2) deleted I will update if I figure anything out.