I had purchased a symposer delete for my '13 Focus ST over a year ago. Over the course of the past year I have been dealing with boost leaks, always chasing the next leaking...boost life right. The past few months it's seems as though I have managed to resolve all of my problems with the exception of one constant, the symposer block off plate. I had removed the intake manifold to clean the carbon from the valves and, in the process, cleaned the intake manifold and somehow managed to source a new o-ring for the plate. This worked for a couple months; however, the leak has returned. No matter what I seem to do this plate seems to be the charge system's " achilles heel". I've inspected the mating surface on the intake manifold for abnormalities that could be outlined as the cause for seal failure with no problems found. The plate itself appears free of visual defects as well. I was curious to know if any of you have seen this problem before or if you are able to shed some light on my situation with any advice you could send my way. Thanks for all your help!