For the above procedures involving the removal of upper intake manifold and throttle body, the following are the steps required for sohc four cylinder engines, The air cleaner housing and the splash shield for the accelerator linkage should be taken off; the accelerator cable should as well be disconnected from the throttle body. Then, remove the connection of the electrical wires coming from the throttle position sensor, idle air control valve and EGR vacuum regulator control if present, and the ground wire of the engine if exist. Remove the PCV hose and mark the vacuum hoses from manifold vacuum tee. Disconnect the transducer hoses for the EGR and the EGR valve and take out the upper intake manifold bolts and studs. Remove any old gasket material from the surfaces, fit a new gasket on the lower intake manifold, place the upper manifold in position and tighten the bolts in a star pattern to the recommended torque. The process of installation is done in a opposite way whereby the removal process was done. To expose the bug, remove the throttle body splash shield disconnecting also the accelerator cable and the electrical connector of the Throttle Position Sensor. The air inlet duct; free the clips or bolts and disconnect the air inlet duct and then remove the bolts that are holding the throttle body and remove the throttle body. Scrub that mating surfaces and set in a new gasket before repositioning the throttle body and fastening the screws. When dealing with fuel rail and injectors, steam clean the engine if required, then refer to the fuel system pressure relief procedure, next remove the negative battery cable and finally the air inlet tube. Remove the fuel supply hose and the return hose from the fuel injectors, then remove the bolts holding the fuel rail then disconnect the electrical connectors from the injectors. Delicately raise the fuel rail and its injectors, if necessary disconnecting the injectors. For installation, the injector O-rings must be checked for damage, if so, it must be replaced and lubed with the engine oil then the injectors must be fitted to the fuel rail. At last, rotate the key ON/OFF to pressurise the fuel system and look for any signs of leakage.