Smart Fortwo NOx Sensor Fix: Dodge Dealer Costs

Had the same nitrogen oxide sensor issue on my 2011 Smart ForFour CDI. The check engine light came on along with poor engine performance and increased fuel consumption. The air-fuel ratio was completely off, causing the exhaust system to work inefficiently. The root cause was a damaged wiring harness connecting to the NOx sensor. The insulation had worn through, creating intermittent connection issues. The catalytic converter was also affected due to the improper readings from the faulty sensor. This turned into a pollution control problem that required immediate attention. For a proper fix, the entire wiring harness needed replacement, plus recalibration of the sensor system. The connector pins also showed corrosion and needed cleaning. This was not a simple DIY job since it required specialized diagnostic equipment to reset the system. While it was not the most expensive repair, ignoring it could have led to catalytic converter damage, which would have been far more costly. Professional repair is recommended for this issue since proper diagnosis and calibration are crucial for the emission control system to function correctly.

Thanks for the detailed insight about the NOx sensor issue. Your experience with the wiring harness really helps put things in perspective, since my Smart Fortwo is showing similar symptoms. Particularly useful to know about the potential catalytic converter complications. Could you share the total repair cost you paid? Also wondering if youve had any emission sensor related problems since the fix? This would help me budget for the repair and know what to expect long term.

A quick update on my Smart ForFour repair costs, the nitrogen oxide sensor issue turned out simpler than initially feared. The mechanic found a faulty cable connection, which was causing the check engine light and emission sensor readings to go haywire. Total cost was 95€ for the repair, much less than expected. The best news is that since fixing the cable connection, the emission control system has worked flawlessly. No more sensor failure warnings or check engine lights. The catalytic converter also runs efficiently now that its getting proper readings from the NOx sensor. Looking back, getting it checked early probably prevented more expensive problems down the line. While my initial concerns about major wiring harness issues were valid, sometimes these emission system problems have straightforward solutions.

Taking the car to my trusted local mechanic was definitely the right call. The whole nitrogen oxide sensor drama ended up being pretty straightforward, turned out to be a loose connection that was throwing off the emission sensor readings. Total repair cost was just 190€, including diagnostics and labor. The mechanic showed me where the wiring had come loose near the diesel engine components and explained how this affected the air-fuel ratio. He also checked the catalytic converter while fixing the pollution control system, which thankfully showed no damage. The whole thing took about 2 hours. Best part is the check engine light is now off and the exhaust leaks were just a matter of tightening some clamps. No issues since the repair, and fuel economy is noticeably better. Really glad I got it sorted before it could cause more expensive problems.