NOVELTY - Electrolysis apparatus comprises: a rectangular electrolysis reactor vessel (10) comprising many electrodes; three neutral plates are inserted in each electrode; a container having two cavities (20) to the water reservoir (21) and a water trap (22); a through hole that connects the electrode cavity and neutral plates; a pair of hose; a down through hole; a pit passage for connecting the water reservoir cavity with a trap cavity; an output gas hole on the top of the water trap cavity; fluid electrolyzer; and many bolt fastener (30).    USE - The electrolysis apparatus is useful to produce hydrogen gas and oxygen for combustion and reduce exhaust emission levels in vehicles (claimed).    ADVANTAGE - The electrolysis apparatus: provides fuel savings; reduces the exhaust gas as waste products of combustion vehicles, thus minimizes air pollution; does not produce toxic gases as waste products of the reaction, where the remainder of electrolytic reactions are only in the form of water vapor, thus environmentally friendly; and can be made easily and inexpensive manner.    DETAILED DESCRIPTION - Electrolysis apparatus comprises: a rectangular electrolysis reactor vessel (10) comprising many electrodes separated by insulator gasket; three neutral plates are inserted in each electrode; a container having two cavities (20) to the water reservoir (21) and a water trap (22); a through hole that connects the electrode cavity and neutral plates on the upper side of the electrolysis reactor; a pair of hose for the circulating line results from the electrolysis of passes up and down the hole into the cavity of the water reservoir; a down through hole that connects the electrode cavity and neutral plate on the underside of the electrolysis reactor; a pit passage for connecting the water reservoir cavity with a trap cavity; an output gas hole on the top of the water trap cavity which is connected to the engine combustion chamber inlet; fluid electrolyzer that is inserted into the electrode gap and the neutral plate, where on the left and right upper pole mounted electrolysis reactor positive and negative connected to a power source; many bolt fastener (30) to tie all the components of the electrolysis reactor container and the container having two cavities.    DESCRIPTION OF DRAWING(S) - The figure shows the electrolysis apparatus in motor vehicles.    Electrolysis reactor vessel (10)    Cavities (20)    Water reservoir (21)    Water trap (22)    Many bolt fastener (30)