VW Crafter NOx Sensor Issues & Exhaust Leak Alert

I encountered a similar situation with my 2015 VW Transporter TDI. The check engine light came on and diagnostic testing revealed the NOx sensor had failed due to a corroded wiring harness connector. The issue was more straightforward than initially suspected. The NOx sensor itself was functioning, but the cable connection had deteriorated from exposure to exhaust heat and environmental factors. The connector pins showed significant corrosion, interrupting the signal to the engine control unit. The repair involved replacing the wiring harness section and cleaning the sensor connection points. While checking this, the mechanic also found minor exhaust leaks at two gasket points which needed addressing. No catalytic converter replacement was necessary. This was not a critical safety issue but required prompt attention to prevent potential damage to the exhaust system and ensure proper emissions control. The nitrogen oxide readings returned to normal after the repair. For your Crafter, I suggest having a diagnostic specialist check the wiring connections first before replacing any major components. Often the NOx sensor itself is fine, and the problem lies in the electrical connections or harness.

Thanks for sharing your experience with the NOx sensor issue. The wiring harness problem sounds exactly like what I am dealing with on my Crafter. I noticed you got it fixed, would you mind sharing how much the repair cost in total? Also curious if youve had any air-fuel ratio or exhaust system problems since the repair was done. My mechanic is suggesting a full sensor replacement but I want to make sure Im not paying for unnecessary work. Just trying to get an idea of what to expect cost-wise and whether a simple wiring fix might do the job. The check engine light is still on and Im getting some concerning nitrogen oxide readings.

Based on your experience, I can confirm the wiring repair resolved the NOx sensor failure completely. The total repair cost was 95€, which covered fixing the faulty cable connection. This was significantly cheaper than replacing the entire sensor unit. Since having the pollution control system repaired, my diesel engine has been running perfectly with no air-fuel ratio issues or further exhaust system problems. The check engine light cleared immediately and nitrogen oxide readings returned to normal parameters. Your situation sounds nearly identical to what I experienced. Based on these results, I would suggest getting the wiring connection checked before committing to a full sensor replacement. A reputable mechanic should be able to diagnose whether the NOx sensor itself is truly faulty or if the issue lies with the electrical connections. The key is addressing the root cause, in many cases, sensor failure warnings stem from connection problems rather than the sensor itself being defective. This type of repair typically resolves the emission control issues without requiring more extensive work.

After getting your advice, I took my Crafter to a diagnostic specialist who checked the wiring first. Turns out you were spot on, the NOx sensor connections were corroded and causing the check engine light to trigger. The mechanic found similar wiring harness issues to what you described. Total repair came to 120€, including cleaning the connection points and replacing a small section of the harness. No need for a full sensor replacement after all. The air-fuel ratio is now perfect and the nitrogen oxide readings are back to normal. Really glad I asked here first, saved me from an unnecessary expensive sensor replacement. The check engine light cleared right after the repair and everything has been running smoothly for the past week. No more exhaust leaks or sensor failure codes. Thanks again for helping me avoid getting overcharged for parts I didnt need.