I disconnected the battery and installed a new one. The car started some missing afterwards, but was kind of Okay. now the Rpm hovers between 600 to 800. Also, lately i have started to notice some residue in the exhaust. Before my last oil change, it was not there. (I believe the oil is a little more than the full mark on the dipstick). Also, there is a little strange noise when the fan starts.
The issue is not huge, but need to get it done with. (For Mental satisfaction also).
Somehow, I didnt feel that Toyota gave sufficient time or care to the car.