1998 Ford Ranger 4.0L with P0171 no other codes

Question

I have replaced the new intake gasket, new bank 1 02 sensor and cleaned MAF. the truck has plenty of power ideals at 900 RPM. but still getting the p0171 code I'm baffled.

Answer 1

P0171 Fuel trim lean

On Ford there is the upper intake manifold gasket which is the plenum and the lower intake gasket, There is also which gets missed is the brake booster hose, a split there usually gets missed, There also the MAF air duct that can have tear that would also set a lean code condition

Answer 2

P0171 FORD Code - Fuel Injection System Too Lean Bank 1

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