very high idle will settle down after a while sometimes. cel 1506 I believe. also surges on deceleration which seems to go away applying a tad of pedal. reset and code return within few minutes. 88 K miles 99 crown vic ex cop car. known to idle a lot in low speed environment most of cars in use life. Ideas to look for and where is the iac valve? also heater seems to not blow air as selected on console(indicative of vac leak, maybe related) where is known vac leak areas on the engine, etc. THANKS!!!