The EGR system is also not provided on all models and made up of the EGA valve, modulator valve and connecting vacuum hoses. The EGA valve is installed in different ways, according to the engine code: with BAG, BLF and BLP the valve is on the left-hand end of the cylinder head and connected to the inlet manifold and exhaust ports, and the coolant cools the exhaust gases; with BGU, BSE and BSF the valve is also on the left-hand end but attached to the air cleaner and throttle housing and to the exhaust manifold; and with AXW, BLR, BLX, and BW the valve is on the rear of the engine, on The engine top cover must be removed to enhance accessibility with special steps needed in various engine codes. In the case of engines BAG, BLF and BLP, disconnect the wiring, hoses that are connected to the EGA valve, de-mount the connecting pipes and un-screw the mounting bolts to remove the EGA valve making sure to reclaim the gaskets and seals. Changing engines SGU, SSE, and SSF, remove the top cover after which disconnect the air hose and wiring and undo the nuts on the EGA pipe flange and follow the pipework to the manifold and throttle housing to disconnect the pipework. In the case of engines AXW, SLR, SLX, and SVY, it is done by removing the top cover, disconnecting the wiring and the hoses, unscrewing the bolts connecting the connecting pipes and finally removing the EGA valve keeping a note on the location of the bracket. Refitting all models would be in terms of undoing the process used to remove it, replacing it with new gaskets and O-ring seals, and maintaining appropriate torque requirements during the examination of the cooling system.