I brought it to CT. CT replaced the distributor(don't remember the name, the one has wires connecting to the sparker). Before bring it to CT, I changed the sparker myslef but didn't help. CT technician help solved the problem.

I also learned you can adjusted the air/gas mix rate by turning a screw which is close to the intake (when you press the gas pad, there is wire controling a wheel, really don't know what it is called). This screw on the corolla controls the gas you can input. It will affect the timing of switching gear. It may help you pass the test because less gas is taken. Somehow, the car may have the same sympton as mentioned. So, mark down the position before you do it.

My old corolla used to be able to make 25km/litter but it is less then 10km now.