Re: Check Engine light and OBD II Code P0171 and P0174
We have to mention the basics first, make sure you have a new fuel filter, clean air filter etc. Then do the fuel pressure test and if it’s OK check the MASS Air Flow sensor for dirt or grime, if it doesn’t see the air going past it, it won’t tell the computer it needs more fuel and both banks (Sides Of The Engine) will be to lean. After that you may have to check for an intake air leak with a smoke test.
2003 Ford E-350SD 4x4
V10 / 4R100 / NV271
Front Axle - 1 Ton Spec Dana 60/King Pin/Open Knuckle/High Steer
Rear Axle - 1 Ton Spec Dana 60/Full Floating
Eaton E-Lockers Front And Rear/4:10 Gears
ARB Differential Covers - Nodular Iron With Dipstick And Drain Plug
Leaf Spring Suspension Front And Rear
46 Gal Transfer-Flow Fuel Tank
ExtremeAire Magnum Air Compressor
Reunel Rear Bumper
On And On ...