Aggressively pulling to the left on acceleration
 

I have noticed the last month my car is pulling HARD to the left when i hit the throttle. When i release it it snaps back to the right and drives perfectly straight with hands off the wheel. Its getting to feel very unstable on the highway. You cant really feel it until 40-70mph or higher. There is 30k miles on the car now (2014 FRS). I took it into the dealer yesterday because my battery would no longer hold a charge and asked them to check it out. They took it for a 1km test drive (not sure how you could leave the dealer and replicate the issue and come back in 1km), then they put it on a ramp to check for bent parts which was pointless because i know the car has never been driven hard, drifted, raced hit anything or any other abuse. After all that they gave me a $70 bill and said the tire was a couple PSI low on one side and "it seems to drive straight". I have had other people drive the car and say it does not feel right. Anyone have any ideas what it could be. I was thinking it could be something in the LSD? Any ideas would be great before i go back to the to the dealer.
Thanks

alignment, blown shock, bad toe rod, axle, unbalanced wheel/tire.

Gremlins

They put it on a ramp to check for bent parts?

Where is this shop? Mexico?

Sounds kinda hokey


You need an alignment. Sounds like your rear toe could be out. (My best guess)

busted linkage or, like these guys, rear subframe.
[ame]http://youtu.be/5YvuHbf0cIk[/ame]

Had a similar issue in a friends. But the tire was a good 15 psi low. Not a couple. May want to double check your tire pressures. Particularly the rears.

Hopefully that's the case and not something more serious.

Are you on stock wheels and tires?

I'm on steel rims and winter tires for the winter. I would expect the alingment would be more logical to check than bent parts. I dread going to the dealer again. The car tracks perfectly straight when your coasting. I figured that would rule out alignment?

This is a misalignment that is induced by longitudinal force applied to the rear axle carrier. Something is broken and allowing it to flop around.

This is a hazardous condition and the vehicle should not be driven. If you are not comfortable with diagnosing and repairing it yourself, have it trailered to a shop.

Do a wheel balance and an alignment check.

alright thanks for the replies. Im going to bring her in for an alignment check, and balance ASAP to see if that fixes her. Il have a good look when i have her on the ramp and see what i can find! I update the final cause/solution. Thanks

I am going to put money on this.

make sure to check for blown-out bushings.

happened to me, turned out one of my rear tires were low on air. filled it up, was good to go!