Intelligent embedded systems represent a novel and promising generation of embedded systems which are able to interact and adapt to the environment in which they operate. When these embedded systems operate in real environmental conditions, the presence of faults or outliers could perturb the acquired datastreams, hence degrading the performance of the envisaged intelligent application. The proposed solution for outlier and fault detection in intelligent embedded systems is meant to promptly detect variations in the statistical behaviour of the acquired datastreams, distinguishing among the occurrence of an outlier, a fault or model bias and activating (whenever possible) suitable mitigation actions. Following a fully cognitive approach, the proposed solution relies on the ability to model and exploit the temporal and spatial relationships present in the acquired datastreams and operate without requiring any a-priori information about the system or the possibly occurring outliers/faults. Experimental results on synthetic and real datasets show the effectiveness of the proposed solution.