I'd like to know what all was done. My brother's has this problem and we've been given many suggestions. I've tried tracing the colored vacuum lines that go from the EATC behind the dash. I haven't found any issues so far. I'd like to get an idea before we remove part of the dash this winter to take a look at it. We have some ideas to what it is, but if someone can pinpoint the exact place, that'd be great.