Check Engine Light Code P0101 | O'Reilly Auto Parts

Diagnostic trouble code P0101 refers to “Mass Air Flow Sensor Circuit/Performance Malfunction”. This may be due to a poorly performing or dirty mass air flow (MAF) sensor, a sensor that needs to be replaced, or issues with the connection between the MAF sensor and the wiring harness. Issues with the MAF sensor typically cause a reduction in efficiency, and may also cause performance issues including rough idle or operation, poor acceleration, and more due to a lack of airflow data being relayed to the engine control module.

Issues related to a P0101 code can often include:

Mass Air Flow (MAF) sensor
MAF circuit/wiring
MAF sensing wire/filament
Barometric pressure sensor
Powertrain Control Module (PCM) software
Air Boot
PCV hose
Intake manifold gasket
Any large vacuum leaks

The necessary parts and tools to clear this Diagnostic Trouble Code (DTC) might differ depending on your vehicle's make and model. If your Check Engine light is illuminated, stop by any O’Reilly Auto Parts and get an O’Reilly VeriScan® for your car, truck, or SUV and get a detailed VeriScan report with more information about your vehicle’s Diagnostic Trouble Code(s), along with possible causes and repair solutions. If you aren’t comfortable making these repairs yourself, our parts professionals can recommend a local shop to make your repair.

Show More Show Less

OBD-II fault code P0101 indicates a “Mass Air Flow Sensor Circuit or Performance Malfunction”. This means that the output of your mass airflow sensor, or MAF sensor, is not within its normal range.

P0101 Code Diagnosis

When you experience a P0101 diagnostic trouble code, your vehicle may be experiencing failure in one of a few areas:

Mass Air Flow (MAF) sensor
MAF circuit/wiring
MAF sensing wire/filament
Barometric pressure sensor
Powertrain Control Module (PCM) software
Air Boot
PCV hose
Intake manifold gasket
Any large vacuum leaks

P0101 OBD-II Code Symptoms

Aside from a Check Engine light, you may notice performance problems, misfires, black smoke from your tailpipe, or poor fuel economy.

Symptoms of a P0101 Code can include:

Check Engine light
Lack of power when accelerating
Coughing/sputtering
Misfiring/backfiring
Trouble idling
Black tailpipe smoke
Poor fuel economy

Whether you notice any symptoms or not, it is not recommended that you drive a vehicle with this code until the problem is diagnosed

Risks of Driving with a P0101 Code

Your vehicle may still run, but driving has the potential to make the problem worse or cause damage to other systems.

What does DTC mean?

DTCs, or Diagnostic Trouble Codes, are generated by data collected by your vehicle’s onboard diagnostics system, or OBD system, and trigger your Check Engine light by identifying problems with one or more of your vehicle systems. DTC codes help explain what the issue is and where it is located.

Learn more about DTC codes

Show More Show Less

What are the most common DTCs?

Some of the most common DTCs include:

P0300-Random or Multiple Cylinder Misfire Code
P0301 through P0308- Single-Cylinder Misfire Codes
P0446- Evaporative Emissions Control System Codes
P0455- Evaporative Emissions Control System Codes-Leaks
P0420 or P0430- Catalyst Efficiency Codes
P0141- Oxygen (O2) Sensor Codes
P0171 or P0174- Lean Code
C0221- Wheel Speed Sensor

Show More Show Less

Can I clear DTCs?

To clear DTCs, you can use an OBD-II code reader to scan and clear the codes. However, this will only temporarily turn off your Check Engine light. If the problem is bigger than a code or sensor reset, the Check Engine light will likely reactivate.

Show More Show Less

If your Check Engine light is on, stop by any O’Reilly Auto Parts location where our Parts Professionals can scan and diagnose your illuminated Check Engine light for free with our exclusive O’Reilly VeriScan code reading service. An O’Reilly VeriScan provides a detailed report of possible causes and solutions or repairs for your illuminated Check Engine light. The O'Reilly VeriScan report, along with the O’Reilly Auto Parts How-To resources can help you understand what parts, tools, and services you need to clear your DTCs and Check Engine lights. If you aren’t comfortable performing any necessary repairs yourself, we are also happy to recommend a local repair shop.