i chenged the plugs. still idles really low(500rpm) but a lot of the roughness is gone. check engine light is still on and still will not pull any codes includeing code 12. How do i adjust the idle speed so i can make it somewhat driveable???

does anyone know how to adust the idle speed?

update. I thought what the hell and i piled my wife and 2 kids into the car and went for a drive. thought maybe if it dies i'll have more pushers. Any way. it died 3 times backing and turning 90 degrees. Then i turned 90 again and straightened the car out. didn't die. i drove it for about 2-3 miles around the neighbor hood. check engine light went out with in about 30sec after i put in into reverse. came back on 10 sec later. once the car got a little heat into it she smoothed out. no stumbling no hesitation and a little higher idle 6-700rpm. i did notice that i have NO speedo. i have 3 fuses currently pulled. radio, clock, and power windows. i don't think any of them have anything to do with the speedo but i could be wrong. i got home and tried backing out again. reverse with 90 turn. no problems. car didn't die or even stumble. i did smell something that smelt kinda like it was running warm but the gauge was reading good. maybe possible plugged or part plugged cat. can't really be sure because i've never encountered that before. I tried using the paperclip to pull codes and i didn't get anywhere. the fan turns on like it should but code 12 will no flash. any suggestions?