I have an odd one. 14 gu712 w/mp7. I'm the 3rd person to work on this so here's the story. Code for def quality. Derate for def quality on the lcd. Sensor was replaced, new def added. Same problem. Not sure what was done by 2nd person. I get it this morning , no codes, derate for def quality on lcd. Cleared lcd warning with the guard dog. Drove for 20 minutes no problems. parked in my bay, off for about 10 minutes. Turn ignition on , lightning bolt and check engine light and def quality derate on lcd all on. after about 5 seconds lightning bolt goes off, a couple seconds later the check engine light goes off. Again I clear the derate message with the guard dog. No codes. I can't find a learned data reset or an acm reset anywhere in ptt. What is going on with this thing? Thanks