Current Augmented Reality navigation applications for pedestrians usually do not visualize tracking errors. However, tracking uncertainties can accumulate so that the user is presented with a distorted impression of navigation accuracy. To increase the awareness of users about potential imperfections of the tracking at a given time, we alter the visualization of the navigation system. We developed four visualization and error visualization concepts and used a controlled Mixed Reality environment to conduct a pilot study. We found that, while error visualization has the potential to improve AR navigation systems, it is difficult to find suitable visualizations, which are correctly understood among the users.