Lack Of Power

Check fuel pressure. See the BASIC TESTING article.
Check throttle cable and then throttle body for sticking and binding.
Check Throttle Position (TP) sensor. See DTC P0122 in the TESTS W/CODES article.
Check Intake Air Resonator (IAR) control system intake air pipe. See the SYSTEM/COMPONENT TESTS article.
Check air cleaner.
Check 3-way catalytic converter for restriction.
Check Manifold Absolute Pressure (MAP) sensor (if equipped). See DTC P0106, P0107 or P0108 in the TESTS W/CODES article.
Check for contaminated fuel.