Good response Jon
I look at it this way and by no means this NOT exactly how it works but the general priciples are similar....
The PC or Laptop you are typing away on
Your car's ECU
you have an eeprom chip in the ECU, that stores all your (factory settings) similar to an eeprom chip for your PC's bios
Then you have a solid state memory chip in your ECU, similar to a PC's hard drive.
All the data is stored on there, it can be overheating in traffic for example so the air/fuel mixture is changed accordingly... You could stall at a junction so more fuel is automatically needed, your car doesn't see it as the fool who just jumped his clutch too early... the list goes on and all the settings are stored over time... Just like your PC does..
Over time your PC slows down and throws up faults etc. Why?
Becuase all these things stored are in the wrong place so you need to defrag your hard drive and put it all back in order, same goes for your registry... old entries need removing and defragged to...
Your ECU has similar issues...
look at an ECU reset as a defrag and a registry clean on your PC and you get why it works...
Your PC is ok, the relevant bits and bobs attached to the motherboard have not failed , its now working much quicker and better.
same as your car's ECU, the sensors on your car have not failed, its just that putting things back in order have made it respond quicker to your varied driving style...
Simplified..... I like simple
As a matter of interest though, I always do this proceedure after a new item is fitted, be it a sensor or a thermostat etc. It seems to run better and I have to say, the results can be dramatic or no difference, just like many people on the forums, how many people in a percentage actually come back and re-post on the same thread three month later?
That could be for anything, wishbones, ECU, thermostat, EGR's... No they oftern get the advice, fix it and mention it no more, why should that proceedure and thread be any different?