100% Free

No Scanner Needed

Carly logo
Prices

emilybrown7

Citroen C6 NOx Sensor Issue

Hi, I have a 2012 Citroen C6 with a gasoline engine. Recently, the check engine light came on. I read the error memory, and it indicates a problem with the NOx sensor. I also noticed a slight exhaust leak. I suspect it might be related. I checked the sensor itself, but I'm not sure where to start. Could a defective cable or plug connection be the cause? The car has 247542 km on it.

Summary of the thread

A 2012 Citroen C6 owner experienced a check engine light, with diagnostics indicating a NOx sensor issue. The owner suspected a connection between the sensor problem and a slight exhaust leak. It was suggested to inspect the wiring harness and connector for damage or corrosion, as these could cause the issue. Ultimately, the NOx sensor was identified as faulty and replaced, resolving the problem.

Did this summary help you solve your problem?

4 comment(s)

guenterjohnson3

The symptoms you describe are indeed indicative of a faulty NOx sensor. The function of the NOx sensor is to measure the levels of nitrogen oxides in your exhaust gases to ensure compliance with emissions regulations. A defective sensor can certainly trigger the check engine light and store error codes. Given the mileage, it's plausible that the sensor itself has reached the end of its service life. However, as you suggested, it is prudent to first inspect the integrity of the wiring harness and connector to the sensor. Are there any signs of physical damage, corrosion, or loose connections?

emilybrown7 (community.author)

Thanks for the quick response! I'll check the wiring again. What exactly should I be looking for in terms of corrosion? Also, if the wiring seems okay, is there a way to test the sensor itself, or is it better to just replace it?

guenterjohnson3

Corrosion will typically present as a greenish or whitish deposit on the metal contacts within the connector. It disrupts electrical conductivity. While it is possible to test the sensor, it requires specialized diagnostic equipment and knowledge of the expected signal outputs. Considering the relatively low cost of the sensor (approximately 95€) and the age of the vehicle, I would advise taking the car to a workshop, so you can be absolutely certain about the root cause.

emilybrown7 (community.author)

Okay, I understand. Thanks for the advice! I checked the wiring as you suggested, and everything seemed fine. Given your recommendation, I took the car to a local shop. You were spot on, the NOx sensor was the culprit; they replaced it. The final repair cost was indeed 95€. The check engine light is now off. Thanks for pointing me in the right direction.

rmh_community_comment_box_header

community_crosslink_scanner_headline

community_crosslink_scanner_intro

community_crosslink_scanner_title

community_crosslink_scanner_price

community_crosslink_rmh_headline

community_crosslink_rmh_intro

community_crosslink_rmh_title

community_crosslink_rmh_subtitle

community_crosslink_rmh_brand

CITROEN

community_crosslink_rmh_model

C6