Question

2001 Ford Taurus SES V6 with engine code P0171 System Too Lean Bank 1, how can I fix the problem?

Answer 1

P0171 Fuel trim lean Bank 1

Lean Bank system are usually caused by vacuum leak such as the PCV hose which can be rupture or even collapsed. Use brake cleaner at spray at suspected vacuum leak area which include intake manifold gasket brake booster hose and not any RPM changes this will lead you to the source and cause of a leak Bank condition.

Answer 2

P0171 FORD Code - Fuel Injection System Too Lean Bank 1
Read more: https://www.autocodes.com/p0171_ford.html