Report "2 way on the highway, engine light started to blink, the car lost some power but kept on going, then check engine light stabilized up to destination. In the evening I moved it and check engine light went off by itself. On the return, the same story so I took it to the garage again. After 1 week they returned it. Then I drove again to that city 150 miles away, on the higway at 75 miles per hour and it behaved great. Yet in the city check engine light went off, blinking, car is shaking especially at stops. Check engine light is sometimes blinking sometimes steady but it is there. What is most likely the problem?"