2002 Pathfinder SE P0171 Error HELP!!!

[dohcser]

Originally I was getting the Errors below:
P1140 - Camshaft Sensor
P0140 - O2 Sensor (Bank1 Sensor 2)

I replace both sensors and the codes went away and now P0171 is present. I cleaned the MAF sensor with the appropriate cleaner, changed the air filter and needed new plugs so changed those also, I cleared the codes but it keeps coming back.
This code is for Bank 1 so I don't think the throttle body gasket or MAF or anything along those lines would be wrong otherwise I would have an issue on both Bank1 and 2, but I am only getting this on Bank 1. Can anyone help me troubleshoot this issue. I do have Torque Pro so I can pull measurements if needed on the sensors.

[AceEngineer]

dohcser,

The MAF is not the only possible cause of this code. Have you checked anything else?

Extracted from my Service Manual;

DTC No. P0171 (Bank 1) P0174 (Bank 2)
Causes: Fuel injection system too lean. Fuel injection system does not operate properly, the amount of mixture ratio compensation is too large. (The mixture ratio is too lean.)

Check:
Intake air leaks
Heated oxygen sensor 1
Injectors
Exhaust gas leaks
Incorrect fuel pressure
Lack of fuel
Mass air flow sensor


AceEngineer

[dohcser]

Sorry for the late response.
Intake air leaks: I sprayed carburetor cleaner around the intake gasket and hoses but didn't notice a difference in idle.

I have a question on the others: incorrect fuel pressure or MAF sensor, wouldn't I get codes on both bank 1 and 2?

My dad did say that when he starts it first thing in the morning it idles rough, but when heated up it seems to run fine, which would still make me lead to the metal expanding such as the intake gasket?

[Slumpert]

Yes it could be a air leak on the intake manifold to cylinder head gasket but if you doused it with carb cleaner and saw no rpm change then that likely is not it.

These motors are know to crack the exhaust manifold so check that first..
Dirty / clogged injector is also very common with age so consider agressive fuel system tune up.

[dohcser]

any advice on troubleshooting the exhaust manifold?