Faulty NOx sensor bank 1 sensor 2 with an internal processor failure; Contaminated or damaged sensor element from exhaust soot, oil ash, or coolant intrusion; Wiring harness damage or poor connector contact at the sensor or controller; Software or calibration issue in the engine control module (ECM) or NOx control module; Exhaust leaks upstream of the sensor allowing false air into the sample; Low DEF quality or level causing abnormal NOx levels that stress the sensor; Failed or failing SCR catalyst causing the downstream sensor to read out of range

DTC codes / P06xx · Computer and output circuits / P06EB

P06EBNOx Sensor Processor Performance Bank 1 Sensor 2

Q: What does code P06EB mean?

NOx Sensor Processor Performance Bank 1 Sensor 2. P06EB means the engine computer has detected a performance fault inside the nitrogen oxide (NOx) sensor processor for bank 1 sensor 2, which is the downstream NOx sensor after the selective catalytic reduction (SCR) catalyst. The computer is not reporting a simple heater or circuit failure; it is flagging that the sensor's internal processing of the NOx reading is not behaving as expected.

P06EB means the engine computer has detected a performance fault inside the nitrogen oxide (NOx) sensor processor for bank 1 sensor 2, which is the downstream NOx sensor after the selective catalytic reduction (SCR) catalyst. The computer is not reporting a simple heater or circuit failure; it is flagging that the sensor's internal processing of the NOx reading is not behaving as expected.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaComputer and output circuits

Symptoms you may notice

Illuminated check engine light, often with no other noticeable symptoms
Reduced engine power or limp mode on some vehicles
Poor fuel economy or increased diesel exhaust fluid (DEF) consumption
Intermittent or erratic NOx readings that may trigger other emissions codes
Possible rough running or hesitation if the fault affects closed-loop emissions control

Common causes, most likely first

Faulty NOx sensor bank 1 sensor 2 with an internal processor failure
Contaminated or damaged sensor element from exhaust soot, oil ash, or coolant intrusion
Wiring harness damage or poor connector contact at the sensor or controller
Software or calibration issue in the engine control module (ECM) or NOx control module
Exhaust leaks upstream of the sensor allowing false air into the sample
Low DEF quality or level causing abnormal NOx levels that stress the sensor
Failed or failing SCR catalyst causing the downstream sensor to read out of range

How to diagnose and fix it

Scan all modules and record freeze-frame data for P06EB and any related codes
Inspect the NOx sensor connector and wiring for corrosion, chafing, or loose pins
Check DEF level and quality, and verify the SCR system is dosing correctly
Perform a manufacturer-specific NOx sensor performance test or bidirectional scan-tool check
Check for exhaust leaks between the SCR catalyst and the sensor
Replace the bank 1 sensor 2 NOx sensor if testing confirms an internal processor fault
Clear codes and complete a drive cycle to verify the repair and confirm the monitor runs

What the NOx processor code really means

P06EB is often set by a sensor that still produces a plausible reading but fails an internal self-check, so a simple live-data glance can miss it.
A weak battery or low charging voltage can cause the NOx sensor processor to log performance faults before any hard circuit code appears.
Technicians sometimes replace the downstream NOx sensor when the real problem is an upstream exhaust leak or a failing SCR catalyst skewing the reading.
Some vehicles require a software update or sensor relearn after replacement, and skipping that step can make the code return immediately.
The code can be stored alongside DEF dosing or SCR efficiency codes, so always diagnose the root cause rather than treating P06EB in isolation.

Can I keep driving with P06EB?

You can usually drive the vehicle short distances to a repair shop, but avoid heavy loads and long trips because continued driving with a faulty NOx sensor can lead to limp mode and increased emissions. If the check engine light starts flashing or the vehicle enters reduced power mode, stop driving and arrange a diagnostic scan.

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.