2001 Hyundai Accent Q&A

2001 Hyundai Accent Question: Possible causes of high nox emission.

My car, a 2001 hyundai accent failed a smog test due to high nox. What could have possibly caused it? -
Answer 1
nox (nitrogen oxide) form in the combustion chamber when the temperature rises above 2500 degrees f. The EGR (Exhaust Gas Recirculation) system helps to lower the combustion chamber temperature, so if it is malfunctioning it will cause high nox. These systems (EGR) often get plugged with carbon and may need to be cleaned out. -