P1143 — Mazda — HO2S Bank 1 Sensor 3 Signal Below 0.45v AF Ratio Too Lean

P1143 (Mazda): HO2S Bank 1 Sensor 3 Signal Below 0.45v AF Ratio Too Lean — what it means, the affected system and what to check before replacing parts.

Meaning, symptoms, causes and checks

HO2S Bank 1 Sensor 3 Signal Below 0.45v AF Ratio Too Lean. Source catalogue definition; confirm applicability using vehicle service information.

Affected system: Powertrain