For about 2 months now I've had a CEL with code 401...EGR flow insufficient. Replaced the DPFE sensor under warranty & had the EGR system all cleaned out, but still a CEL with code 401. I've been told that some of the EGR piping can get a buildup of crud that's hard to get out so I'm going through the EGR system myself...anyone have any advice before I go crazy with my wrenches & torches?
91 SHO plus black/black, work in progress
