My 2003 Toyota Echo became shake regardless it is in neutral or drive (manual transmission)

Hi All,

As title says, my car that has 146k and had no major problem so far. Today
afternoon I went to the grocery, drove 3 miles, did a shopping for 10-15
minutes, came back, started to drive a car, and noticed a fine shaking. I
stopped at the red light, then at a 4-way stop, and put the stick shift into
neutral. Regardless the shift was in neutral or anything between 1 and 4,
the car continued to shake (it was like a fine tremor). I parked my car for
about 1-2 hours, went outside, restarted, same issue, and now the Check
Engine light came up. Any idea? I am taking my car to AutoZone to check
for the codes, but want to have some idea in advance what could cause the
problem. Is it possible that I have to change battery? The last time I
changed it was in November 2012, and I live in Texas (I know, I know...) :-(

Thank you in advance for your time and reply.

h99x