Disconnect the cable from the negative battery terminal, then raise the vehicle and support it securely on jackstands. Disconnect the oxygen sensor electrical connector(s) and, while working under the vehicle, apply penetrating oil to the exhaust Y-pipe-to-manifold studs and nuts, as they are usually rusty. Remove the nuts holding the exhaust Y-pipe to the exhaust manifolds from below, and disconnect the EGR pipe from the exhaust manifold. Remove the engine lifting bracket, then take out the nut holding the oil dipstick tube support at the front of the manifold and pull the dipstick tube up and out of the oil pan. Next, remove the mounting nuts and separate the exhaust manifold(s) from the cylinder head, ensuring to remove the old gaskets. Check the exhaust manifold for cracks and ensure all stud threads are clean and undamaged, making sure the mating surfaces are clean before reinstalling the manifolds. If replacing the exhaust manifold with a new one, remove the oxygen sensor, clean its threads, and coat them with high-temperature anti-seize compound before transferring it to the new manifold. Position the exhaust manifold and new gasket on the cylinder head, install the mounting nuts, and tighten them in the correct order using a torque wrench, ensuring to tighten in three equal steps until the specified torque is reached. The remaining installation steps follow the reverse order of removal, after which start the engine and check for exhaust leaks.
