How to Replace the Exhaust Manifold in a Mazda6

Take the negative battery cable from the terminal. Remove the main silencer and pre-silencer, then remove the three-way converter from the side on which the manifold is being replaced.

Remove the stud bolt and the front pipe. Unplug the two heated oxygen sensor connectors, then take out the exhaust gas recirculation (EGR) pipe.

Loosen and remove the exhaust manifold fasteners. Lift the exhaust manifold from the engine and discard the gasket.

Scrape the mating surfaces to remove any gasket material, dirt and carbon deposits. Wipe the surfaces with solvent. Check for damage.

Install the new gasket to the cylinder head. Position the V over the gasket.

Tighten the exhaust manifold fasteners in sequence, workout out from the center. Torque the bolts to 14 to 19 foot pounds.

Reconnect the EGR tube and the two heated oxygen sensor connectors. Connect the front pipe with a new gasket.

Replace the three-way converter and then reconnect the pre-silencer and the main silencer. Attach the negative battery cable to the terminal and secure it.

Start the engine and allow it to run for several minutes. Check for exhaust leaks and proper engine operation.