Dose it have a throttle idle control sensor

Usually if you have an engine performance concern like this, it is due to too much or not enough air getting into the engine. This can be from an air intake leak, vacuum leak, sticking idle air control valve, a mass air flow sensor that is reading inappropriate barometric pressure reading, and similar components to that. A good diagnostic tool can monitor data from various components. IAC valve's do stick. MAF's do go out of range. And you can have an air intake leak or starvation of air causing idle concerns. Of course, checking base fuel pressure and ignition system performance is also important.