[BB_cuda]

Yozh, per post #61, this is what i did to drain. I used a manual vacuum pump thing for siphoning fuel but it didn't fit. I only got about 1.5 gallons to come out. I'm unsure if all will come out with this method. I should have had about 69% of full system since i had only driven 4000 miles and that would have left about 9000 of the normal 13000 mile range. 9/13=69%. Perhaps I got shorted on my last DEF topoff. No matter, as its getting removed in the near future. I need to get access to a lift to remove exhaust.

Mik325, that was a great idea to purge the line of urea and replace with water. Be careful for cool weather though. Urea freezes at 19F and of course water at 32F. You may want to redrain tanks to get water out if it is real cold where you are.

How much urea did you collect in your draining?

EDIT: Something just occurred to me. Since my SCR wasn't turned off during 3500 miles of using Ecotune programming and EGR was blocked, I may have been spraying at a higher rate. If car were without mods, both EGR and SCR function to reduce NOx. With EGR blocked, SCR was on its own to reduce NOx for 4000 miles. This is a hypothesis of mine, no data to back it up. I do not know to what level SCR was "closed loop" trying to control NOx running the Ecotune.

Does anyone out there running EGR blocked notice a higher rate of refilling urea?