No adjustment on the engine for the idle speed. If the idle speed is too high - then check these possibilities; first - check for a vauum leak - cracked / damaged vacuum hose (replace as necessary). Then, check the idle air control (IAC) valve. Also, check and clean the MAF sensor - at the air intake hose. Be sure to use an aerosol spray cleaner specific to mass air flow sensors.
The parts are readily available from these many on-line sources, www.partsgeek.com, www.rockauto.com, www.discountautoparts.com, www.autopartswarehouse.com, www.jcwhitney.com - to list only a few possibilities.
In fact, they (RockAuto) list the idle air control (IAC) valve from around $72.00 for your vehicle.