[nates6969]

Hi I have a mercury topaz V6 and lately the check engine light has been always on, turns on about 10 seconds after starting. It started happening after a vaccuum line got disconected off the EGR. I reattached the line but still the light comes on. Also nonw when you start it up it revs up to about 1200 then drops to 200 then usually goes back up to steady idle but sometimes it stalls or it idles up and down from 1500 to 500 and back and forth. Could this be a problem with the EGR? and if it is would it be the valve or solinoid? If you could help me out that would be great! also if I were to get it plugged into a computer would it tell me which is shot or would it give me one basic code? Thanks