I am REALLY sceptical about this whole thing - can't see any logic in it, but my level of knowledge may not be upto the mark. However, I noticed plenty of articles and forum post talking about this. Here is a quote from an Alfa Romeo owner (this guy's car seems to have become completely new!!!! -
My GT 2.0L JTS has been idling a bit rough recently, and it felt like a few of my horses had flown south for the winter. In addition, my climate insisted on only blowing hot air, no matter what temp I dialled in.
Having trawled through various threads, the ECU reset fix was mentioned several times as a cure for both symptoms.
So, today being a quiet day in the Christmas break, I decided to attempt the ECU and throttle re-set procedure -which is as follows if you haven't seen in other threads :
1. Disconnect battery for 45 mins
2. Reconnect battery, and turn ignition to MAR for 90 secs
3. Turn off and leave 90 secs
4. Start engine WITHOUT pressing throttle and let the car idle for 15 mins (I repeat, do not touch the throttle whilst the car is idling)
5. Turn engine off and leave for 10 minutes
6. Start the car and go for a drive, using a number of styles (eg town, motorway, thrash etc)
So I did this, and my GT is reborn ! Faster, smoother, more torqier, even idle - it's bloody fantastic ! I can't believe how different the whole car feels.
It nearly cured the climate problem (well it blows a bit cooler) so if anyone has any tips on how to fix, let me know.
But the cherry on the icing on the cake was something I didn't expect, it seems to have cured my 'stepping' drivers window problem that I had given up on !!
Now the driver's window goes up and down as smoothly as the proverbial baby's bum.
So, if you're thinking of trying the ECU/Throttle reset and you have a hour or two on your hands this festive break, give it a go - it might work miracles for you to !