So what was the verdict on the DISA valve?

I'm here in Houston too and have been having a boatload of trouble since it's started warming up... I've got the 1800-2000RPM whistling, misfire codes, crap acceleration and rough idle on my '02 3.0i... I've checked the boot and that looks kosher, so I'm leaning towards the DISA or a MAF that is going out.