I have been modded for a couple years now, and I never thought of resetting my ecu when I had my mods installed. Should I reset it? Or did my ecu already learn on its own over time?

 

It has probably learned it by now. It doesn't hurt to do it every once and while. I do it when I clean my K&N. Seems to make a little change, I drive hard afterwards hoping for better results.
Some do it, some disagree... give it a try. Worst part is reseting clock and radio presets.

 

how do I reset my ecu? -in lamens terms, lol

 

Get the car warm then park up. Switch the car off and pull the ECU fuse shown below for about 10 mins (this removes power to the ECU) Replace it, start the car up then go and find a long stretch of road and give it redline through the gears. The ECU will quickly learn where to set its fuelling and ignition timing. The next step is to get the idle sorted. You will notice the car really struggles to idle and cuts out. To relearn, park up and let the car go through 3 cycles of the cooling fan coming on and off. its then set. It will eventaully learn anyway, but its quicker using the cooling fan method.

Fuse can be found behind the fuse cover inside the footwell:



Or remove the negative battery terminal and wait for 10 mins

Copied from s2kuk faq

 

^ what the guy said