NOVELTY - A reformer system comprises reformer catalyst capable of reforming fuel to hydrogen and carbon monoxide, and water gas shift catalyst in fluid connection with the reformer catalyst and in fluid connection with exhaust gas source. The exhaust gas source comprises water. The water gas shift catalyst is capable of reacting carbon monoxide with water to produce hydrogen and carbon dioxide.    USE - Used as fuel processor useful in converting hydrocarbon fuel, e.g. methane, propane, natural gas, gasoline, diesel, gas oils, oxygenated hydrocarbons to hydrogen or to less complex hydrocarbon for vehicle system (100).    ADVANTAGE - The invention eliminates complicate designing of vehicle system. It eliminates the use of external water supply. It eliminates separate air intake for reformer, thus reducing the complexity of the system and reduces cost of the system. It allows carbon monoxide concentration in the reformate to be decreased while increasing the hydrogen gas concentration in the reformate. It controls temperature of reformer, thus reducing risk of damage to reformer caused by excess temperature in the reformer.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for:    (1) producing hydrogen in reformer system comprising supplying fuel to reformer catalyst, supplying exhaust bleed containing water from exhaust source to the reformer catalyst, removing fuel using reformer catalyst to produce hydrogen and carbon monoxide, and reacting the carbon monoxide with water from exhaust bleed using water gas shift catalyst in fluid connection with and downstream of the reformer catalyst to produce carbon dioxide and hydrogen;and    (2) using reformer system comprising supplying fuel to reformer catalyst, supplying exhaust bleed with water from an exhaust source to the reformer catalyst, reforming fuel using reformer catalyst to produce hydrogen and carbon monoxide, reacting carbon monoxide with water from the exhaust bleed using water gas shift catalyst in fluid connection with and downstream of the reformer catalyst to produce carbon dioxide and hydrogen, supplying hydrogen and oxidant to fuel cell, and generating electricity using fuel cell.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of the vehicle exhaust system.    Engine (12)    Oxidation catalyst device (14)    Particulate filter device (16)    Nitrogen oxide adsorber device (18)    Selective catalyst reduction (20)    Oxidation catalyst (22)    Vehicle system (100)