There are several components that make up this system, the initial component is the smog pump. Check the lines coming from the smog pump to make sure they are not cracked and leaking.
system to lean bank one 02 sensor ?
check the maf sensor
where is the crankshaft position sensor a bank 1 circuit malfunction on a 2003 f150 at
bank 1 is the passenger side of the engine
Trouble code P0171 means: Fuel System Too Lean (Cylinder Bank 1)
The drivers side cylinder head is bank 2
Trouble code P0171 means: Fuel System Too Lean (Cylinder Bank 1)
bank 1 is the passenger side of the engine
Bank 1 is on the passenger side. Bank 2 is on the drivers side. The O2 sensors are screwed into the exhaust system. Follow the exhaust manifold rearward and you will find the O2 sensors.
passenger side
Bank 2 would be the bank of cylinders on the drivers side of the engine containing cylinders 5, 6, 7, and 8. Bank 2 O2 sensor would be threaded into the bank 2 exhaust system directly leading from bank 2 cylinder head.
Bank 1 is the pasenger side of the engine