Abstract: The present invention is a reversion control device including a housing with a proximal end and a distal end. The reversion control device further includes at least one reversion cone, a stationary vane and a flapper. In one example, the reversion control device includes an oxygen sensor for monitoring the oxygen content of the engine for routine operations or for diagnostic purposes. In an example, the housing includes an expansion chamber to house the reversion cone, the stationary vane and the flapper. In another example, the stationary vane is housed within the reversion cone. In yet another example, the reversion control device is integrated within an exhaust manifold elbow.