Performance problem with 94 GT 5.0

[bflynn]

My 94 GT 5.0 starting having a problem. In low gears it is the most noticeable. It feels like I am pulling and lead anchor, it just won't go. I am getting about 50 miles per tank less on fuel milage. Top end seems to still be there. If I kick it into passing gear, it just ups the rpm's and does not acclerate. I have had it tuned up, replaced the catalytic converters, the oxygens sensors. It is better but I can still be beat at low end by hondas. Just prior to replacing the 2 O2 sensors, I was receiving the following codes. Any ideas what my problem is?

172 Oxygen sensor not switching - system is or was lean - Single, Right or Rear HO2S - Fuel control
176 Oxygen sensor not switching - system is or was lean Left or Front HO2S - Fuel control
181 Fuel system was lean at part throttle Single, Right or Rear HO2S - Fuel control
189 Fuel system was lean at part throttle - Left or Front HO2S - Fuel control

[HOOLS96GT]

have you checked ur fuel pressure? fuel filter? these code say to me that it needs more fuel. im a ford tech in upstate ny wish i had it here i could diag it better. u have use to a scan tool? try to check ur mass air voltage should be .5 - .9 volts running.any new codes since u change those components?

96 gt pi conversion and new goodies to install stage 2 cams and springs.
bryan
IRISHMOTORSPORTS NY

[bigwhitecobra]

I vote for you to change your fuel filter, put a guage on your schreder(*sp?) Valve and see what your pressure is before and after. That may help more than anything. Check that and let us know.