What to do about under steer on my car?

The vehicle has electronic traction control, and either it is malfunctioning, or badly designed.

Either way, that is what you need to look into, not the suspension.

Here is a quote:

{ ... Electronic Stability Control (ESC) is designed to assist drivers in maintaining control of their vehicle during extreme steering maneuvers. ESC senses when a vehicle is starting to spin (oversteer) or plow (understeer), and attempts to correct the vehicle's course by automatically controlling the throttle and applying the brakes at individual wheels. The control you'll feel is astonishing.

An important aspect of ESC, Journey's traction control system is tuned for on-road activity during normal operation. When wheel spin occurs, the system maintains traction by applying the brakes and in some cases closing the throttle, to minimize spin during acceleration.

All-Wheel Drive anticipates the need for added traction and responds to wheel slippage by transferring power to the rear wheels. This gives greater driving performance and increased safety and security. The system operates only on demand, thereby reducing unnecessary fuel consumption. ... }

I would suggest pulling the fuse on the traction control system, to see what the difference is.

If there is no difference, then you know what the problem is basically, and just have to find the electrical problem.

First I would check the tire pressure of all 4 wheels against the sticker on the driver's door near the latch to verify the front tires are not over inflated. Also verify that it has the correct tire size.

Next I would have an alignment done. I know it's a 2012, but you never know if they hit a curb or something causing the alignment to be out. Here is a Wikipedia link to information about alignment. http://en.wikipedia.org/wiki/Wheel_alignment

Wider front tires, and narrower rear tires can help, but this generally only applies if the original tires have been changed with wider on the rear and narrower on the front.

Why would you "need" max power in a hard corner? Sounds like you need a link to a good driving school.

Sorry about previously. in case you nonetheless desire the reply, Graham suggested his vehicle replaced into pushing like a PIG. i imagine Graham might want to have had slightly oversteer because his again end got here to visit and hit the wall. The wing configurations of the nostril and again wing and weight jackers contained in the vehicle may result the lower than/oversteer. OVERSTEER: also observed as "loose." Describes a condition in which the rear of the vehicle is risky by way of a lack of aerodynamic downforce or mechanical grip. Oversteer might want to be led to by technique of a lack of rear downforce, too a lot the front downforce or inadequate rear grip. --------------------------------------... UNDERSTEER: also observed as "push" or "tight." Describes a condition in which the vehicle does no longer opt to reveal contained in the corners by way of a lack of aerodynamic downforce or mechanical grip. Understeer might want to be led to by technique of a lack of the front downforce, too a lot rear downforce or inadequate the front grip.