To remove and install the 2.3L 4-cylinder engine, start by removing the fuel system pressure and disconnecting the negative battery cable. Remove the air cleaner-to-throttle body hose, disconnect any cruise control cables and hoses, if equipped, and remove the PCV valve. Disconnect the wiring and fuel hose from the cold start injector and remove it if necessary. Repeat this for the auxiliary valve, and remove the intake manifold brace, and label the vacuum hoses at the intake manifold and loosen the clamp for the rubber connecting pipe on the air-fuel control unit and remove the boot from the intake manifold. Remove the manifold bolts and the actual manifold itself. For installation, clean the gasket mating surfaces and install the intake manifold with new gaskets and tighten the bolts to 15 ft. lbs. Install intake manifold brace and air-fuel control unit connecting pipe, then auxiliary valve, cold start injector, and PCV valve. Reconnect all vacuum hoses, electrical connectors, reconnect the negative battery cable and start the engine to bring it up to normal operating temperature. For the 2.8L 6-cylinder engine, you follow similar first steps such as draining the radiator coolant, removing the throttle cable and disconnecting various hoses and lines and removal of the manifold. Cleanse gasket surfaces, install the manifold using new gaskets, and connect all parts again. For the 2.9L 6-cylinder engine, drain the fuel pressure, remove the battery lead and the throttle switch wiring and manifold assembly. Install the inner part of the manifold with a new gasket, tighten it and reconnect all of the hoses and electrical. For the 2.3 liters and 2.4 liters 5 cylinders DOH, relieve fuel pressure, disconnect the battery cable, remove the injector cover and the fuel rail with injectors. Disconnect various hoses and pull off the intake manifold but assure you have clean mating surfaces before you install the new gasket and manifold. Reinstall all components, reconnect battery cable and test run engine, checking for leaks.