Before undoing the exhaust manifold, you should first disarm the negative terminal on the battery, remote ground terminal. Then, raise the front of the vehicle and support it securely on jackstands, then undo the engine splash shield fasteners and shield. Then, the oxygen sensor electrical connectors should be unscrewed and the sensors taken out, then the crossunder pipe bolts should be removed in order to withdraw the crossunder pipe that is connected to the exhaust manifolds. On the rear manifold, disconnect the right front drive axel, lower the car and unbolt/nut the exhaust manifold heat shield to in order to remove the heat shields. Last, take mounting bolts and separate the manifold from the cylinder head and for this, it is preferable to use penetrating oil on bolts. As to installation, the mating surfaces must be washed to remove gasket debris the manifold must be examined for distortion and cracks, the use of a straightedge for warping is recommended. In the event of excessive wear, have the surfaces of the manifold' taken to an automotive machine business for refinishing. Align the exhaust manifold and place on a new gasket, tighten the mounting bolts by hand but just enough so that you can distinguish the direction of the cylinders and exhaust port. Loosened the mounting bolts in sequence starting with the middle and then, gradually to the completion of the desired torque value. The rest of the installation is done in the opposite of the removal as described above. You should check the exhaust systems for leaks, right after the installation of the exhaust manifold and before starting with the following steps Switch on the engine and look for any exhaust leak between the manifold and the cylinder head and also between the manifold and the exhaust pipe.