my friend has a 2000 civic and i need to know when changing the o2 sensors if i have to do anything to the computer

 

If you're just replacing them with the same type, no. It would be a good idea to reset the ECU though, that way the ECU will start from scratch with the new sensor readings instead of having the old in memory and then trying to make sense of the new.. Just disconnect the battery cable before you start, by the time you're done changing the sensors the ECU will have lost it's memory and will be reset.

 

You could also reset the ecu by pulling the ecu fuse found in the fuse box under the hood, wait 15 mins. and plug fuse back in.

 

what they both said cause I just recently did tthat