Resetting ECU

Been seeing quite a few responses to issues, with the answer being reset the ECU. (Pull battery for 15 minutes)

Does someone want to explain the ECU to me?
Why can it be helpful in fixing minor issues?

What if I was to reset it, then drive like a "granny" for a week, how would my normal driving be affected than if I had driven like a racer for a week? Gas mileage???


thanks

 

The ECU is the Engine Control Unit - The computer brain for the engine parameters. It hold some things in memory even with the battery disconnected for short periods, but if you take the battery off for 15+ minutes and/or touch to the wires (off the battery mind you) together you purge all the charge and the computer forgets everything but the hardwired stuff.
This gives you a (most likely) higher idle and can clear codes and "clean up" unexplained hiccups initally. It also gives you a chance to reset all the fuel mapping. So if you drive drastically differently, you may see a small change in your mpgs, but for the most part the ECU is programmed to maintain within a certain parameter range, so it'll will adjust to try to make that happen.