P0171 Nissan - March 2002

Question

P0171 - System Too Lean Bank 1

symptoms

• Engine Light ON (or Service Engine Soon Warning Light)
• Excessive Fuel Consumption

Answer 1

Hi there,

There are a couple things that are common causes for this. You could have a problem with the mass air flow sensor, the front O2 sensor, sometimes an intake manifold gasket leak will also cause this code. A low fuel pressure issue caused by a bad fuel pump could also cause this code.