wrose

Had my 996 turbo at track Saturday for a DE event-1st track visit . Car ran great for 5 sessions-very strong compared to my old S/C M coupe. But during last session it started to have idle surge and when I oitted it surged up/down 400-900 rpm and eventually stalled down but CEL didn't come on . On drive home CEL came on and i couldn't accelerate very well . about every 20 kms I would have to pull off and recycle the key . when home I checked the turbo hoses and looked for any vaccum hoses off-all looked ok .Codes stored were P1101(innput variable charge measurement) , P1249(boost pressure deviation below minimun), and P1508(function monitoring torque comp.) . when i unplugged the MASS it idled fine . I ordered a new MASS and installed it today and cleared stored codes . Idle was still surging so not sure what's next? Does it require a drive cycle with the new MAFS ? Should I disconnect the battery?-I have Durametric cable.
TT has a Vivid 650 upgrade kit with Softronic tune done in 2008 by precious owner.
what do you think?
Thanks
Wayne

Kevin

I'd lay some monies on an intake leak, blown hose or connection.

Search for the DIY intake leak test.. The battery disconnect doesn't do crap if you have all those codes..

wrose

Kevin
You were right!!
Today I went back at the car and removed the fender liners to re-check the hoses . Found the right boost hose off the intercooler -guess i missed it the first time around!
Thanks again
Wayne