The intake manifold is made of aluminum and has two parts, the upper and lower one; the upper intake manifold is enough to remove only when some work on spark plugs or valve cover is to be done. To achieve complete removal the fuel system pressure has to be discharged, the negative terminal has to be loosened. The bolts of Intake Air Temperature sensor need to be removed and the electrical connector needs to be disconnected and the tube for the air intake and the upper housing of the air filter. Also, electrical connectors at the IAC motor, TPS, and MAP sensor must be disconnected, as well as vacuum hoses from several parts. The accelerator cable as well as the cruise control and transmission control cables, if installed, must be disconnected. To replace or repair the EGR pipe the EGR pipe is disconnected with the EGR valve and also with the intake manifold by just unbolt it and then the oil dipstick is removed. When the upper and the lower intake manifolds are removed as a unit then the subsequent procedures include the detaching of the electrical connector to the Coolant Temperature Sensor, fuel injector harness connectors in addition to the fuel rail, pressure regulator and injectors assembly. This part should be removed when replacing servicing the intake manifold plenum, however; it can stay on if not necessary. To remove the intake manifold and its gasket, a number of bolts holding the intake manifold support bracket and the intake manifold bolts and washers are required. For inspection the straightedge and feeler gauge should be employed to check for warpage on the mating surfaces of the intake manifold and cylinder head and if this is greater than specified limits, the intake manifold or cylinder head must be resurfaced or replaced. A new manifold gasket should be installed when the manifold is being installed and the intake manifold bolts should be tightened to specification in a star pattern with the remainder of the installation in the reverse of the removal process.