Mercury 7T4Z-5E212-A Catalytic Converter

To replace the catalytic converter in four-cylinder engines, start by raising the vehicle and placing it securely on jackstands. Locate and disconnect the downstream oxygen sensor on the upper central part of the catalyst. Unscrew and remove the downstream oxygen sensor/catalyst sensor from the catalyst. Loosen the fasteners on the clamp that secures the front end of the catalyst to the turbocharger. Remove the nuts and bolts that secure the flange at the rear end of the catalyst to the exhaust pipe. Remove the catalytic converter and discard the old gasket between the exhaust down pipe and the catalyst mounting flange. Installation is the reverse of removal, using a new gasket and new fasteners if necessary.

To remove the catalytic converter on V6 engines with the 3.0L engine's rear cylinder head and 3.5L engine's front or rear cylinder head, raise the front of the vehicle and place it securely on jackstands. Remove the engine under cover. Disconnect the upstream and downstream oxygen sensors, remove both oxygen sensors, and remove any heat shield if equipped. Remove the fasteners securing the catalyst's upper mounting flange to the exhaust manifold, as well as the lower mounting flange to the exhaust pipe. Pull the exhaust pipe down to clear the lower end of the catalyst. Remove the catalyst from the exhaust manifold and discard the old gaskets between the flanges. Installation is the reverse of removal, using new flange gaskets.

To replace the catalytic converter in V6 engines, start by raising the front of the vehicle and placing it securely on jackstands. Remove the engine under-cover. Locate and disconnect the upstream and downstream oxygen sensors. Remove both oxygen sensors. If there is a heat shield on the catalyst or exhaust manifold, remove the heat shield bolts and remove the heat shield. Remove the fasteners that secure the heat shield mounting bracket and remove the bracket. Remove the fasteners that secure the catalyst's upper mounting flange to the exhaust manifold. Remove the fasteners that secure the lower mounting flange to the exhaust pipe. Pull the exhaust pipe down enough to clear the lower end of the catalyst. Remove the catalyst from the exhaust manifold and discard the old gaskets between the exhaust manifold flange and the upper catalyst flange, as well as between the lower catalyst flange and the exhaust pipe flange. Installation is the reverse of removal, using new flange gaskets.