How to Replace the Exhaust Manifold in a Mazda6

The Mazda 6 has carved out its own niche in the highly competitive midsize car segment. In 2003, the Mazda 6 has consistently received rave review for its stylish design, handsome interior and pleasing performance. Owners hang on to their Mazda 6s, so a good used model is a great find. Here are the steps to install the exhaust manifold on the 3.0L engine.

Remove the Exhaust Manifold

  • 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 Exhaust Manifold

  • 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.