why would a ford explorer run rough after unhitching the battery and the service engine soon light come on?
i have a 2004 ford explorer 4.0 and i went to start it and it wouldn't start. so i changed the
fuel filter and unplugged the battery; then i plugged the battery back in; and it wouldn't
start. i finally got it to start; but it's running rough. the only way i can get it to idle is by
holding down the gas pedal. or it will just die. after i unhitched the battery and plugged it
back in; the service engine soon light came on. can anyone please tell me why this is.
You reset the ECM back to factory settings, so now you need to run a relearn on the system, that usually takes about 20 minutes drive time, if the check engine light doesn't go out during that time then something needs attention. With newer vehicles you just don't disconnect the battery without using a code retention device or you might windup with an undriveable vehicle.
Have you retrieved the codes to see what the computer has to say? It's possible that you may have unplugged something by accident. A quick code check will tell you which system to check. Simply disconnecting and reconnecting the Battery will not disable the vehicle. While it is true that the system will have to re-learn the engine and may idle funny for a while, that won't prevent you from driving it. Check the DTC's and see what cha got.