Loss Of Power

Check air intake system. Also, ensure throttle plate and linkages operate properly.
Check ignition system. See the BASIC TESTING - 2.5L article.
Check fuel delivery system. See the appropriate SYSTEM/COMPONENT TESTS - EEC (2.5L) article.
Check for restricted exhaust system.
Check EGR system. See the appropriate SYSTEM/COMPONENT TESTS - EEC (2.5L) and the TESTS W/CODES - EEC (2.5L) articles.
Check engine compression. Check engine mechanical condition. Check timing belt, intake manifold gasket, camshaft and valves.
Perform QUICK TEST. See the TESTS W/CODES - EEC (2.5L) article.
On M/T models, ensure clutch is operating properly.
On A/T models, ensure transmission is operating properly.
Check for dragging brakes.