I feel your pain...there are so many hits about this issue but no real definite resolution. Our TW went merrily for a couple of years and then one day we began having the random drop in idle while waiting at traffic lights and/or stalling. It starts immediately and off you go. I have cleaned the throttle body and ISC, reset the ECU and all runs sweetly for 3 or so weeks and then within a few days all the issues creep back. Most times the reset temporarily works but in recent weeks it hasn't. I purchased a new ISC and it basically did zip other than it introduced a new issue by having a consistent low idle speed for the first week (even at cold start where you had to keep the revs at 1,000 RPM for 30 seconds for it to have a stable idle) then one morning it went up to 1200 RPM on its own ! Our local road service guy suggested that if it does not become stable with the new ISC then I should look at replacing the ECU from an identical model (TW wagon Series 2 with tiptronic 4 speed trans).....it's a good car but geeze if I new of a reputable Mitsi specialist in Adelaide I'd be happy to throw some dollars at it.