This seems like a vacuum leak to me. I know you had it tested but you must check everything, and I mean everything... even the brake booster. I know I now sound like a broken record, but this was our 2 year issue with mixture issues.
Make sure you 100% have the proper MAF, these are at least 2 for the 2000MY and they are NOT compatible without an ECU flash.
__________________
______
Jon
1966 912, 1976 911
1986 944, 2000 Boxster
|