Scion Xb 2012 hesitation problem

I bought a new 2012 Scion Xb about 6 months ago and it had a 3 second hesitation when I would step on the gas pedal. Unfortunately, it would only happen randomly. I recorded each time it would hesitate and after 2 months I brought the car back to the dealer and the dealer consulted with Toyota and they replaced all the injectors and spark plugs (dealer had the car three weeks.) After these changes I drove the car another month, but it did not correct the problem. The problem occurs when I start off from a stopped position and turn to the right or left. It occurs randomly and at different times during the day. It may skip a few days- but it doesn't go away.

The dealer gave me a second new 2012 XB and I have driven this car about 2000 miles. Believe it or not -this new car is exhibiting the same symptoms as the first car. I tried using high test gas - it didn't resolve the problem. I love this car - but I cannot live with this dangerous hesitation problem. It is like the computer has a virus and randomly creates this hesitation problem. I am sure the dealer thinks I am the problem, since, it doesn't happen when his mechanic tries to duplicate the problem.

Any suggestions?? This is a living nightmare!