OBD-II code guide

P1101 Intake Air Flow System Performance

P1101 usually means the measured airflow does not match the expected airflow for the engine.

What it means

The intake airflow model is out of range, often because of leaks, MAF problems, or throttle body deposits.

Common symptoms

  • Hesitation
  • Rough idle
  • Poor fuel economy
  • Check engine light
  • Stalling in some cases

Likely causes

  • Dirty MAF sensor
  • Intake air leak
  • Dirty throttle body
  • PCV or vacuum hose leak
  • Air filter or duct problem

First checks

  • Inspect intake duct clamps.
  • Look for cracked PCV or vacuum hoses.
  • Check MAF and throttle data.
  • Avoid replacing parts before smoke-testing leaks.