I brought the ST3 back to the dealer today. If you are counting, that’s the third time in 3 weeks that I brought the bike in for this problem. But this time I think they figured out what it is that’s causing the bike to idle low and the tack jumping up and down, feeling like it will stall on. The bike feels like it’s running on one cylinder. I’m just glad this bike comes with a two year warranty.
Later that day I got a phone call, apparently the exhaust spring was broken and they will be replacing the ECU. This was a problem on the 2004 ST3, mine is a 2005, but it sure looks like it suffers from the same bad components. The new ECU should be arrive in about 10 days.