OBD Guide

P1171

Fuel System Lean During Acceleration

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Loss of power when accelerating
  • Jerking or lag during acceleration
  • Increased fuel consumption
  • Unstable engine operation
  • Check Engine Light Is On

Causes

  • Dirty or faulty air flow sensor
  • Air leaks in the intake tract
  • Fuel pump malfunction
  • Clogged fuel injectors
  • Problems with the throttle position sensor

How to Fix

  1. Check the tightness of the intake tract
  2. Clean or replace the mass air flow sensor
  3. Check fuel pressure
  4. Clean or replace fuel injectors
  5. Check the operation of the throttle position sensor

Related codes

Error P1171 by Vehicle Brand