Ludhiana, Feb. 14 -- The operation of Bharat Stage (BS) VI model buses under Punjab Roadways and PRTC is facing disruptions due to faulty nitrogen-based sensors and a shortage of their replacements. For the last few months, the Punjab Roadways and PRTC workshops in Ludhiana are awaiting these sensors, officials aware of the matter said.

According to the workshop staff, these nitrogen-based sensors (NOx) are essential for controlling emission levels. These sensors monitor nitrogen oxide in the exhaust and are key to the selective catalytic reduction system, which uses AdBlue, a urea-based solution to turn harmful NOx into safe nitrogen and water. However, when the NOx sensor fails, the engine's control unit struggles to adjust the emissio...