Our superintendent got a "real good deal" on some Blue Bird transit buses a few years back. Twice a week a "Regen Needed" light would blink on my dash. The mechanics would have to do a "standing regen", then the bus would be fine for a few days. The buses were sent back to the dealer to be reprogramed and now they regen while being driven at intown speeds filling the inside of the bus with noxious fumes! The first time this happened to me I got an instant headache and my throat became raw. Anyone else driving these mobile chemical factories?