Vacuum leak or unmetered air entering the intake tract downstream of the mass air flow sensor; Contaminated or failing mass air flow sensor element; Faulty or clogged manifold absolute pressure sensor; Wiring damage, corrosion, or poor connection at the MAP or MAF sensor connectors; Restricted intake or dirty air filter element causing skewed airflow readings; Exhaust gas recirculation valve sticking or leaking, altering intake pressure; Engine mechanical issues such as a vacuum leak from a failed intake gasket or PCV hose

DTC codes / P00xx · Fuel and air metering and auxiliary emission controls / P00B8

P00B8MAP - Mass or Volume Air Flow Correlation Bank 2

Q: What does code P00B8 mean?

MAP - Mass or Volume Air Flow Correlation Bank 2. P00B8 indicates that the powertrain control module has detected a mismatch between the manifold absolute pressure sensor signal and the combined mass or volume air flow sensor readings for bank 2 of the engine. The computer compares expected airflow derived from the MAP sensor against actual airflow reported by the MAF or volume air flow sensor, and it sets this code when the two values deviate beyond a calibrated threshold for a sustained period.

P00B8 indicates that the powertrain control module has detected a mismatch between the manifold absolute pressure sensor signal and the combined mass or volume air flow sensor readings for bank 2 of the engine. The computer compares expected airflow derived from the MAP sensor against actual airflow reported by the MAF or volume air flow sensor, and it sets this code when the two values deviate beyond a calibrated threshold for a sustained period.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaFuel and air metering and auxiliary emission controls

Symptoms you may notice

Illumination of the check engine light, often with no other noticeable symptoms
Rough idle or unstable engine speed, particularly when the engine is cold
Hesitation or stumble during acceleration from a stop
Reduced fuel economy as the computer struggles to calculate the correct air-fuel ratio
Intermittent surging or lack of power under load
Occasionally, a rich or lean exhaust condition that may trigger additional codes

Common causes, most likely first

Vacuum leak or unmetered air entering the intake tract downstream of the mass air flow sensor
Contaminated or failing mass air flow sensor element
Faulty or clogged manifold absolute pressure sensor
Wiring damage, corrosion, or poor connection at the MAP or MAF sensor connectors
Restricted intake or dirty air filter element causing skewed airflow readings
Exhaust gas recirculation valve sticking or leaking, altering intake pressure
Engine mechanical issues such as a vacuum leak from a failed intake gasket or PCV hose

How to diagnose and fix it

Inspect the air intake tract for cracks, loose clamps, or disconnected hoses between the MAF sensor and throttle body
Check the air filter element and replace it if it is visibly dirty or restricted
Use a scan tool to view live data for both MAP and MAF sensors and compare readings at idle and during a snap throttle test
Perform a visual inspection of the MAP and MAF sensor connectors and wiring for corrosion, chafing, or loose pins
Clean the MAF sensor element with a dedicated MAF cleaner following the manufacturer's procedure
Test the MAP sensor with a vacuum pump and multimeter to verify its voltage output changes smoothly with applied vacuum
Smoke-test the intake system to locate any vacuum leaks that are not visible during a visual inspection

What the correlation code really tells you

A dirty MAF sensor often causes this code without setting a MAF-specific fault because the sensor still reports a plausible signal, just not one that matches the MAP sensor's expected value.
Bank 2 designation on a V-engine refers to the cylinder bank that does not contain cylinder number one, so technicians must confirm which bank is bank 2 before replacing parts on the wrong side.
A leaking or stuck-open EGR valve can skew MAP readings at idle and trigger this correlation code even when both sensors are functioning correctly.
After any repair, the code may remain in memory until several drive cycles complete, so clearing it immediately and returning the vehicle without a road test can lead to a false comeback.
On some engines, a failing intake manifold gasket creates a vacuum leak that only appears when the engine is cold, making the code intermittent and difficult to reproduce during a warm-engine diagnostic.

Can I keep driving with P00B8?

The vehicle is generally safe to drive to a repair shop, but avoid heavy acceleration, towing, or long trips until the fault is diagnosed because incorrect airflow calculations can cause poor fuel economy and eventually damage the catalytic converter. If the engine runs rough or stalls, stop driving and arrange a tow.

Tools that help

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Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.