To remove the exhaust manifold, first disconnect the cable from the negative terminal of the battery, ensuring to disconnect the Intelligent Battery Sensor connector on 2015 and later models if equipped. Raise the front of the vehicle and support it securely on jackstands, then remove the engine splash shield. Detach the exhaust pipes from the exhaust manifolds, and for 6.1L engine models, remove the air filter housing and coolant recovery bottle. For 2015 and later 5.7L Challenger models and all 6.4L engine models, remove the cylinder head before proceeding. Connect an engine hoist to the engine and remove the engine mount-to-subframe fasteners. Disconnect the oxygen sensors' electrical connectors and remove the sensors, then remove the exhaust manifold heat shield mounting bolts/nuts and the heat shield if equipped. Remove the bolts retaining the exhaust manifold to the cylinder head and raise the engine enough to allow for the removal of the exhaust manifold. For installation, clean the manifold and head gasket surfaces, check for cracks and flatness, and replace the exhaust manifold gaskets. Install the exhaust manifold(s) and fasteners, tightening the bolts/nuts to the specified torque in a center-to-ends pattern, approaching the final torque in three steps, and reinstall the heat shields. Apply anti-seize compound to the exhaust pipe-to-exhaust manifold bolts and tighten them securely, completing the installation in reverse order of removal.