What Does P006B Mean?
The ECM has detected a correlation error between the MAP (Manifold Absolute Pressure) sensor and the exhaust pressure sensor. These sensors measure pressure on opposite sides of the engine — intake manifold and exhaust system respectively. The relationship between them should follow predictable patterns based on engine load and RPM. A mismatch indicates one sensor is faulty or there is a physical restriction affecting pressure readings. The driver may notice reduced power, poor turbo response (if equipped), or rough running.
Common Causes
30%
Failed or drifted exhaust pressure sensor
25%
Clogged or kinked exhaust pressure sensor supply tube/hose
20%
Faulty MAP sensor providing incorrect readings
15%
Restricted exhaust (plugged catalytic converter or DPF) causing abnormal exhaust back-pressure
10%
Exhaust leak before the pressure sensor skewing readings low
Diagnostic Steps
1
Compare MAP and exhaust pressure sensor PIDs at key-on engine-off. Both should read approximately atmospheric pressure. A sensor that reads significantly off at rest is likely failed.
2
Start the engine and monitor both sensors at idle and under load (snap throttle or road test). MAP should show vacuum at idle; exhaust pressure should be slightly above atmospheric at idle and rise with load.
3
Inspect the exhaust pressure sensor tube for soot clogging (especially on diesel vehicles with DPF). Disconnect the tube and blow through it — it should be clear. Clean or replace if restricted.
4
Check for exhaust leaks upstream of the exhaust pressure sensor using a visual inspection and by listening for exhaust tick/hiss sounds. A leak allows pressure to escape, causing artificially low readings.
5
If a DPF-equipped vehicle, check the DPF differential pressure and soot load readings. An overly clogged DPF will cause abnormally high exhaust back-pressure.
Estimated Repair Cost
$100 - $600
Parts + labor, varies by vehicle and location
The ECM has detected a correlation error between the MAP (Manifold Absolute Pressure) sensor and the exhaust pressure sensor. These sensors measure pressure on opposite sides of the engine — intake manifold and exhaust system respectively. The relationship between them should follow predictable patt...
The most common cause of P006B (MAP - Exhaust Pressure Correlation) is: Failed or drifted exhaust pressure sensor
Typical repair costs for P006B range from $100 to $600, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Safe to drive for short distances. If caused by a restricted exhaust (plugged cat/DPF), continued driving can cause overheating of exhaust components, which is a fire risk in extreme cases. Reduced power is expected. Diagnose within 1-2 weeks; sooner if power loss is significant.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P006B to identify the root cause.
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Quick Info
Category
Powertrain
System
Exhaust System
Difficulty
Type
Generic (SAE)
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