How will a vehicle handle if it has too much toe out?

If the vehicle has excessive or too much toe out, it will become unstable at higher speeds. The reason for this is that the suspension geometry will be unable to effectively control the tire contact with the road. If you were looking at the vehicle from above, you would notice the front of both tires pointing outward (for front toe settings). This will cause understeer while going straight, meaning the car feels like it wants to keeps going straight instead of turning. If the toe out is significant enough, the car will pull to the side that has the most positive toe.