Thanked: 549. An OBD tool can be used in a preventative way provided: You know and understand what a specific sensor is measuring. What the normal measurements are suppose to be. What the tolerances / limits are. What these variances means and how it relates back to the mechanicals. What corrective action needs to be taken. This problem only affected early Discovery 4 TDV6 models from 2010 to 2013 in the VIN range AA510178 to DA676456, along with Range Rover Sport and the 2013 Range Rovers that used the same TDV6 engine. The problem was subject to a Land Rover Technical Bulletin issued in 2013, and then a later bulletin LTB00487V6 issued in 2015. But this was only Two solve this there are two solutions, one is to replace the faulty part with a new item which is costly and the same problem can occur with time. The second solution is to clean the EGR valve and block the EGR pipework with some metal plates which stop the exhaust gasses from being recirculated into the inlet manifold. 2010 Land Rover Discover 4 TDV6; 3.0-litre, six-cylinder, turbo-diesel; six-speed automatic; wagon - $94,990* My biggest problem with the Discovery 4's interior wasn't so much the interior but UcoXnF.