i took the car back this afternoon.
dealer did test drive again, and replicated the problem with no codes logged by the computer. dealer reported the case to "TSE" and was advised to replace IVM. dealer test drove 380 miles with no more problem. - I will keep my fingers crossed and drive carefully down on the road.
on this problem, dealer had driven my car >1000 miles for 17 days in April. my damage is only some gas - still under warranty (i am lucky).
dealer said they did the same to couple of other 7'ers and no one came back.
lesson learnt: dealer is not always the best, hahaha... will go to the local indy when warranty runs out. quarterto8 had given me some good contacts in Houston.
again, I love you all for sharing your experience and knowledge!
Last edited by dingxhng; 05-01-2012 at 06:44 PM.