I think I solved the problem.
I found a crack tube. It is a small U shape rubber tube that connecting the plastic tubes that goes from the TB to EVAP valve (I am not sure the exact name but it is part of the EVAP system).
I replaced the tube and the SES light went off after several trips.
Hope this is the final solution...

That is the EVAP purge valve. When that valve is commanded open by the PCM, it pulls vacum through the evap sytem (charcoal canister etc.) and pulls slight vacum on the fuel tank to check integrity of the evap system. The crack in that "U" tube at the purge valve would explain the DTC. You were losing vacum.