اردو
DTC Codes / Powertrain

P0171 — System Too Lean (Bank 1)

Powertrainmedium

The engine computer is adding a lot of extra fuel — too much air or too little fuel.

Symptoms

  • Check engine light
  • Rough or up-down idle
  • Hesitation when accelerating

Common causes

  • Vacuum leak
  • Dirty or faulty MAF sensor
  • Weak fuel pump or blocked filter
  • Cracked PCV pipe
  • Exhaust leak before front O2 sensor

How to fix

  1. Smoke test for vacuum leaks
  2. Clean MAF with MAF cleaner
  3. Check fuel pressure
  4. Watch fuel trims on a scanner

Can I keep driving?

Yes; repair soon.

These are the general meanings. Some companies use a code a little differently — confirm with a scanner and your car's service manual.