Sorry to revive an old tread but I'm in the process of trying to get the EGR controller on my om617 swap working correctly. There isn't a lot of information out about this subject and this was one of the only threads I was able to find that actually discussed the function of the EGR control besides just trying to bypass the thing entirely. Im looking for information on mainly how changing the tooth count on the ring gear might effect the function of the EGR system.