Peakie

Hi, I've got a 2004 impreza sti fitted with alcatek ecu, since the colder weather sometimes my car will stall cos the revs drop really low, it's done it about 3 times in the last month but it usually happens if I'm in a bit of traffic at a junction and the traffic is just moving along stop/start or if i have to come to a sudden stop and press the clutch in the revs drop quite low, it only does this after about 4 or 5 miles upto that is fine and after that it's fine.? I've just cleaned the iacv which was quite dirty and all seems ok so far, just wondered if it does start doing it again is there any way of upping the revs.? Or would it need a map tweek for the colder weather.?? Cheers.