P0171 Mazda - 1/1, Bank 1 system too lean, what does it mean?

Question

Last weekend while driving a long distance on highway, the check engine light was on. The light could occasionally disappear but most of time it was on. Kind of intermittent. Driving smoothly as usual without an obvious fuel efficiency loss. What could the problem be?

Answer 1

Hi there,

Several things can cause this code. Basically the code means there is a lean fuel mixture. This can be a result of a faulty mass air flow sensor, low fuel pump pressure, intake manifold or exhaust leaks as well as the front or rear O2 sensor.

Answer 2

P0171 MAZDA Code - Lean Air/Fuel Ratio Bank 1
Read more: https://www.autocodes.com/p0171_mazda.html