Question 1

What does P0171 mean?

Accepted Answer

The P0171 code indicates that the engine air/fuel mixture is running too lean on Bank 1 (the side of the engine containing cylinder #1). Too lean means there is too much air and not enough fuel in the mixture. The ECM is adding more fuel than expected via long-term fuel trim to compensate, indicating a real underlying problem. This can lead to engine damage if the lean condition is severe or prolonged.

Question 2

What causes P0171?

Accepted Answer

Vacuum leak, MAF sensor dirty or faulty, Clogged fuel injectors, Low fuel pressure

Code P0171 — Système trop pauvre (Banque 1)

Causes courantes

Codes associés