I am sure you fixed this but the best way to fix it is simply put some time on a road, about 150 miles but could be as short as 75 miles. The filter has to get cleaned out and once the back pressure is reduced the limiter will be reset.
I have an 07 and want to take off all of the exhaust stuff that drags down the MPG. I live in a county without emissions so there is not a problem with that. What I can't find is a place/way to get the mods done. Can you tell me more about your modification?
Thanks