P0171 Toyota -

Question

Checked for Intake air leaks - None
Replaced front heated oxygen sensor
Cleaned fuel injectors
Checked for Exhaust gas leaks - none found
fuel pressure checked good
Cleaned Mass Air Flow (MAF) sensor and replaced air filter
Checked Positive Crankcase Ventilation (PCV) hose connection no leaks/cracks in hose found
What else could be causing this fault. I am over due for a smog test. Please advise.

Answer 1

P0171 Fuel trim lean Bank 1

Check the MAF air duct for leaks

 Do a visual at the MAF air duct, Just like this vehicle with a P0171 the false air was found at a tear at the MAF air duct.