Lexus 25052-20020 Exhaust Manifold Converter Sub-Assembly, No.2

Disconnect the negative cable from the battery. Unplug the oxygen sensor wire harness and the clamp over the harness. If you're installing a new exhaust manifold, remove the sensor. Remove the upper heat insulator from the manifold by removing the exhaust manifold heat insulator bolts. Apply penetrating oil to the exhaust manifold mounting nuts/bolts. Disconnect the exhaust pipe from the exhaust manifold. Remove the exhaust manifold brace (some models have two braces) and lower heat insulator by unbolting the exhaust manifold flange brace near the front engine mount. Remove the nuts/bolts and detach the manifold and gasket by removing the exhaust manifold fasteners at the cylinder head. Use a scraper to remove all traces of old gasket material and carbon deposits from the manifold and cylinder head mating surfaces. If the gasket was leaking, have the manifold checked for warpage at an automotive machine shop and resurfaced if necessary. Position a new gasket over the cylinder head studs. The marks on the gasket should face out (away from the head) and the arrow should point toward the rear (transaxle end) of the engine. Install the manifold and thread the mounting nuts/bolts into place. Working from the center out, tighten the nuts/bolts. Reinstall the remaining parts in the reverse order of removal. Run the engine and check for exhaust leaks.