There is an article in the May FMCA magazine about a recall on C-15 Cat engines in Country Coach and Custom Chassis Products, because of a fire hazard from the DPF (diesel particulate filter) system.
Custom Chassis Products was the join venture between Monaco Coach and Navistar. so the C-15 Cat engines that are in the recall maybe the ones that went into Marquis coaches. Therefore if you have a Marquis with a C-15 that is equipped with a DPF system, I would give Cat a call to verify your status regarding the recall.
Gerald