P1426

Ford

EGI Mini - MAF Failed Out Of Range

Definition source: Manufacturer reference catalog
Definition verification: Not independently verified for display.
Time: Varies by diagnosis and vehicle | Diagnostic difficulty: Medium
Medium Severity

The engine computer has detected a mass airflow (MAF) signal outside the range it expects. The MAF measures incoming air so the computer can calculate fueling. This code identifies a detected condition, not proof that the sensor itself needs replacement. Exact applicability and procedures depend on the vehicle's model, year and engine.

Report an error with this code

⚠️ Before You Begin (Safety First)

If the engine stalls, loses power severely, or runs so poorly that you cannot drive safely, stop in a safe place and arrange inspection. Otherwise, arrange diagnosis soon; do not replace parts based on the code alone.

Common Symptoms

  • There may be no noticeable symptoms if the computer can compensate for the MAF reading.
  • The engine may idle roughly or hesitate if an incorrect airflow reading leads to incorrect fueling.
  • Fuel economy or engine performance may worsen if the airflow signal is sufficiently inaccurate.
  • The check-engine light may be on.

Common Causes

  • The MAF sensor may be contaminated, damaged, or producing an implausible signal.
  • A loose, damaged, corroded, or poorly connected MAF electrical connection may disrupt the signal.
  • A wiring or circuit fault may cause the MAF signal to fall outside the expected range.
  • An intake duct leak, obstruction, or other airflow problem may make measured airflow inconsistent with engine operation.

Diagnostic Steps

  1. Check whether the engine is running dangerously poorly; if it is stalling or losing power severely, stop driving and seek assistance.
  2. With the engine off, inspect the air-intake duct and accessible connections for looseness, visible damage, or disconnection.
  3. With the ignition off, visually check the MAF connector and nearby wiring for damage or a connection that is not fully seated; do not pull on the wires.
  4. Check whether the air filter is visibly obstructed or incorrectly seated, and correct only what the vehicle's owner information supports.
  5. Have the codes and scan data checked before replacing or cleaning the sensor; use vehicle-specific service information for any electrical testing.

When to Call a Professional

Check for related codes and compare MAF scan data with other engine data while inspecting the intake path and sensor wiring. Confirm the cause with vehicle-specific service information and appropriate circuit tests before replacing the MAF sensor.

Compare component listings

Confirm diagnosis and vehicle fitment before buying. A listing does not prove that a part needs replacement. We may earn a commission from qualifying purchases.

Search Amazon Search eBay

Commonly Asked Questions

Does P1426 prove the MAF sensor is bad?

No. It reports a MAF signal outside the expected range. Wiring, connector, or intake-air problems can also affect the reading.

What does the MAF sensor do?

It measures incoming air so the engine computer can calculate fueling. An inaccurate signal can contribute to poor running or performance.

Can I keep driving with this code?

That depends on how the engine runs. If it stalls, loses power severely, or is unsafe to control, stop driving. If it runs normally, arrange diagnosis soon and monitor for worsening symptoms.

Should I replace the sensor first?

No. Check related codes, scan data, the intake path, and the sensor circuit before deciding whether the sensor has failed.

Browse Available Code Guides

Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.