On their way to Patna from Chapra on the rath,senior BJP leaders Sushma Swaraj and Arun Jaitley became slightly unwell on Tuesday evening. Jan Chetna Yatra convener Ananth Kumar attributed the illness to certain technical flaws in the air-conditioned bus during the 80-km journey. Kumar said one of the bus generators developed a snag giving out toxic carbon monoxide that mingled with air-conditioning to cause suffocation. Swaraj and Jaitley were occupying the rear portion of the bus. Advani and Kumar,on the other hand,would often take the hydraulic lift to greet supporters on the way and would therefore get fresh air at regular intervals. Though Swaraj and Jaitley had retired to their hotel room soon after reaching Patna on Tuesday evening and had skipped a meeting at Gandhi Maidan,they were back,fresh and healthy,on Wednesday morning at Advanis press conference. Earlier,the bus got stuck briefly while crossing the rail-cum-road Koelwar bridge near Ara. The ring fence of the lift touched the bridge ceiling causing dents. The driver,however,managed to take out the bus without further damage and delay. The Isuzu bus,bought from Pune,is being driven by Advanis favourite drivers from Punjab. The 15-seater bus has a hydraulic lift to take three-four persons to the bus roof. There is a kitchen,a bathroom,tables,power points and an intercom to give instructions to the driver. In the front,there are three seats besides the drivers.