Check engine light and shaking.

What is your question?

My check engine light came on last month for a day. I started the car the next day and the check engine light was no longer on. It turned back on yesterday and has been on since. Today while I was driving on the highway, I was accelerating and the car began to shake. I let my foot off the gas and the shaking stopped. Check engine light's still on... Any ideas? Don't know if this is relevant, but the transmission was replaced at 130,000 with one that had 27,000 miles. And last time I got an oil change, they said my tranny was slightly leaking fluid.