fluxedup

why dont you google soot content of fossil fuels. you would deny the corrosive nature of exhaust gasses and soot? By the way, you might also want to use a block off plate on the top of the egr tube to avoid vacuum leaks, or do you believe that your allen screw is airtight? It might not be much of an issue , but if yours has an electrically controlled egr valve it probably is not shutting properly. I wonder why the egr tubes all rot out in the first place?