What causes NOx sensor to go bad?
NOx sensors monitor the level of nitrogen oxide being emitted by a diesel vehicle to ensure compliance with emissions regulations. Common causes of failure include soot buildup on the sensor, ECU water intrusion, and/or damage to the cable, which will cause the check engine light to illuminate.
How long should a NOx sensor last?
For those who have purchased your vehicle from new, manufacturer warranties for the NOx sensor can vary immensely, with the typical warranty periods ranging from around five to ten years. There may also be a mileage limit to consider.
Where are the NOx sensors on a diesel engine?
The assembly uses two NOx sensors: the first sensor (referred to as NOx sensor 1) is located near the turbo downpipe and measures engine out NOx. The second sensor (referred to as NOx sensor 2) measures NOx levels exiting the SCR catalyst.
Where is the NoX sensor on a SCR?
The assembly uses two NOx sensors: the first sensor (referred to as NOx sensor 1) is located near the turbo downpipe and measures engine out NOx. The second sensor (referred to as NOx sensor 2) measures NOx levels exiting the SCR catalyst. The SCR assembly contains a catalyst brick that requires DEF, or diesel exhaust fluid, for activation.
Do you have a NOx conversion efficiency fault?
It looks to me like you do not have a NOx sensor fault at all. NOx Conversion efficiency is more of a logic fault, not a sensor problem. From the limited information I have, I can guess that your NOx sensors are working correctly, but it is not sensing enough of a NOx reduction. Meaning you have a problem in the SCR system.
What does ammonia look like on a NoX sensor?
If too much DEF is injected into the exhaust, the SCR brick can become saturated with ammonia and some of it will exit the SCR assembly. This is called “ammonia slip”. To a NOx sensor, ammonia and NOx look the same.