P0171 2004 Ford F150 Lean Code cant go above 60mph
 

2004 Ford F150 4.6L XLT 110,000

Primary Code P0171 System Too Lean Bank 1

Truck has been driving rough and hesitating on the road for about a month. When on the highway the truck will not go over 60 mph without jolting and misfiring. I have attempted to locate potential vacuum leaks by running a smoke test through the brake booster line. I found a leak from the EGR and replaced the part. I have cleared the PCM several times after repairing a component and still getting the same code. Replaced the following: O2 sensors, MAF sensor, spark plugs and coils, pcv valve, EGR and fuel filter. Also cleaned fuel injectors and add CATA clean to the fuel tank.

Request assistance with other possible issues that would cause the lean code.

Running CarScan Tool RepairSolutions 2. I have attached the reading freeze for my truck.

https://cimg9.ibsrv.net/gimg/www.for...48316317f.jpeg
https://cimg1.ibsrv.net/gimg/www.for...6fd8e6a9bf.png
https://cimg4.ibsrv.net/gimg/www.for...995d1fd568.png

When you replace components that could have been faulty, you need to reset the PCM. Did you do that ?

Reply to Hanky
 

Yes I have cleared the code via my scan tool and disconnected the battery for 30 min. Still showing the lean code. I’m thinking of chasing wires and replacing vacuum lines. Not really sure where to go from here.

When you remove the negative cable from the battery , you need to connect a jumper wire from the negative cable end to the positive cable end for a few minutes to allow the capacitors in the PCM to discharge.

Can you post the fuel trim readings at idle and 2100 RPM for us to examine? Thanks.