you might try taking the ground loose for the battery for a 5 minutes to reset the computer and follow these steps to set the idle. This is out of the book so....... Idle Air Trim
Idle Air Trim is designed to adjust the Idle Air Control (IAC) calibration to correct for wear and aging of components. When engine conditions meet the learning requirement, the strategy monitors the engine and determines the values required for ideal idle calibration. The Idle Air Trim values are stored in a table for reference. This table is used by the PCM as a correction factor when controlling idle speed. The table is stored in Keep Alive Random Access Memory (RAM) and retains the learned values even after the engine is shut off. A Diagnostic Trouble Code (DTC) is output if the Idle Air Trim has reached its learning limits.
Whenever an IAC component is replaced or cleaned or a service affecting idle is performed, it is recommended that Keep Alive RAM be cleared. This is necessary so the idle strategy does not use the previously learned Idle Air Trim values.
To clear Keep Alive RAM, refer to PCM Reset in Section 2. It is important to note that erasing DTCs with a scan tool does not reset the Idle Air Trim table.
Once Keep Alive RAM has been reset, the engine must idle for 15 minutes (actual time varies between strategies) to learn new idle air trim values. Idle quality will improve as the strategy adapts. Adaptation occurs in four separate modes. The modes are shown in the following table.
IDLE AIR TRIM LEARNING MODES Transmission Range Air Conditioning Mode
NEUTRAL A/C ON
NEUTRAL A/C OFF
DRIVE A/C ON
DRIVE A/C OFF
