Car idles low

[trbotaln]

Everytime I unplug the negative side of the battery to install something, when I put it back on,my car will idle really low for a couple times of driving it and then it seems to go back to normal. Is this normal? Does the ECU have to reset itself or something?

 

[96TSi_Chris]

You are resetting the ECU when you take the battery terminals off. The ECU has to relearn the fuel trims and so on. Ive always found it best to let the car sit at idle for 10-15 min before driving it.