When driving north on i-95, my car began to slow down even though i had not released pressure on the gas peddle, so i accelerated. as soon as i accelerated, the car then began to run extremely rough, the rpm monitor fluctuated back and forth, and the began to slow down even more. i looked in the rear view mirror to check traffic as i prepared to pull off the interstate and saw smoke coming from the rear of the car. when i stopped and exited the car, smoke was then bellowing profusely from the front right side of the hood and upper right tire rim, so much so that i thought the engine was about to explode. it should also be noted that the check engine light never came on. a tow truck was called and now i'm waiting for my local toyota dealership to open so that i can find out what is wrong with my car. a similar energy surge and rough driving occurred approximately one year ago and my car was towed in, but no problem could be detected. the problem stopped as mysteriously as it appeared, with no serious reoccurrences until yesterday, 9/7/15. in 2014, the mechanic chalked the problem up to possibly bad or cheap gas.