Vehicle Shudder problems of the 2011 Ford Mustang

The electronic throttle body is defective. The car loses power and nothing happens when I step on the gas, but the engine does not turn off. I have pulled over and the car shakes pretty violently. Once I turn it off and back on everything seems fine for a while but eventually does it again. Got the code p2111.

2011 shelby gt500 - brought this car in for grinding into 2nd gear (all other gears seem fine. . At the moment). Was told that all Ford would do is replace 2nd gear, which they did and was also told that it was our driving and replacing 2nd gear is all that they would do. We were told by the regional rep and engineer that. . . Quoted - "we have to have the clutch all the way down to the floor before shifting (engaged). The reason it will grind between 1st and 2nd and not into the other gears is because vehicle has bigger jump in rpm from 1st to 2nd. Vehicle is shifting correctly as designed. ". Totally disagree. . . Very upsetting since it is their flagship car and am told this is all they will do.

After I first purchased the vehicle I noticed a vibration in the shifter which eminated from the transmission. I took it back to the Ford dealership aprroximately a month or more later and was informed there was no issue with the transmission. However, to this day there exists a very noticable vibration with increasing episodes of difficulty changing gears between # 5 to 2, either shifting up or down. It is more noticable when down shifting. On more than one occasion I had to shift into another gear above what I was attempting to go for because the gear would not connect into proper placement. This caused a brief back up when going onto the freeway with several cars behind me due to the transmission being stuck in a particular gear setting (#3). This cleared once I changed to a lower gear ratio.

The car makes a grinding and knocking noise when I accelerate gently and coast at low speeds up to 15 mph in 1st gear. It doesn't make the knocking noise when I accelerate hard nor does it make this sound when im cruising above 15 mph and give it gas. I am concerned that the transmission may go out and cause an accident.

I am intermittently unable to shift into 1st 2nd and now 3rd gear. Several people have almost rear ended me when I could not get the car into 1st gear after stopping at a red light. This issue is potentially a serious safety issue if someone were to be in a situation where they needed to move their car quickly and could not get the car in gear to move. The car also has a vibration when running between 2500-3000 rpm. I am very concerned for my safety driving this car. I have not taken this car to the dealer due to their own ambition that this is normal and there is no fix.