P006B: MAP - Exhaust Pressure Correlation
The P006B code indicates that the Engine Control Module (ECM) has detected a correlation issue between the Manifold Absolute Pressure (MAP) sensor and the Exhaust Gas Recirculation (EGR) or exhaust pressure sensor. This typically means the MAP sensor reading does not match the expected exhaust pressure, often due to a stuck EGR valve, clogged exhaust passages, or a faulty sensor. The ECM uses these sensors to monitor engine load and emissions, and a mismatch can lead to performance issues.
01. Most Common Causes
- Faulty MAP sensor
- Stuck open EGR valve
- Clogged exhaust gas recirculation passages
- Exhaust pressure sensor malfunction
- Wiring or connector issues in the sensor circuit
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or hesitation
- Poor fuel economy
- Failed emissions test
- Possible engine misfire
03. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the MAP sensor and EGR valve for damage or carbon buildup.
Step 3: Test the MAP sensor voltage with a multimeter and compare to manufacturer specs.
Step 4: Check the EGR valve operation by applying vacuum or using a scan tool to command it open/closed.
Step 5: Inspect wiring and connectors for corrosion or loose connections.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is generally not recommended to drive long distances as it can cause poor performance and increased emissions. Short trips may be okay, but have it diagnosed soon.
How much does it cost to fix?▼
The cost varies depending on the cause. Replacing a MAP sensor or EGR valve typically ranges from $50 to $150 for parts, plus labor if done by a shop.