I have had a bad problem with surge and hesitation. i successfully replaced my egr and bpt, as well as cleaned out the tube. I have no blockages as i can feel the exhaust pulsations from the bpt tube. To remove the egr was easy you just need a 12mm stuby wrench. now my question is what else could be the cause of bad surge and hesitation?? cuz replacing the two valves changed nothing. TIA!! Charles