Something's wrong with my engine.

[dante2086]

First of all, the check engine light is constantly on. And for the love of me I can't find a good place to do a diagnostic in my region.
And when I drive, when I approach a speed of like 140 kmph, the check engine light starts flashing, then I feel this resistance, like the car is slowing itself down. Prior to this, my yaris could go 170 without coughing.
Oh, and it stutters when I start it in the morning. But starts fine the rest of the day.