Broke down yet again

[trdodd07]

Had the truck break down on me last month. I was able to limp it to a KW dealer and they had replaced the EGR valve, Nox sensors, Exhaust back pressure sensor, did a dpf cleaning, and a regen. Got back on the road yesterday and picked up a load only to get about 500 miles from the shipper and bam....warning lamp comes on for Nox sensor fault, then the check engine light comes on for engine protection derate. I guess I am just wanting to know what I should be looking out for when they tell me what is wrong and what needs replaced, so I don't get screwed again by these crooks. The bill for the break down last month was $3,600, and this is the 3rd time I've had this thing in for Nox issues that never seem to get fixed.

I asked the guy working on the truck if it is common for an EGR Valve to just unexpectedly fail, and he said not really, but it can happen. So, I guess that is my next question. Can an EGR Valve fail randomly, or is there other underlying issues that led to it's failure that should have been investigated as well? I was able to see the old one, and it didin't look bad on the inside. Had some soot build up, but nothing outrageous. It did fail in the closed position though. I won't be able to get into the shop until tomorrow to hear what is going on now with it, but I have a good feeling it's going to have something to do with the work that was done last month. It's absolutely frustrating to spend that kind of money, only to see that nothing is being properly fixed. Truck and engine model is in my sig if anyone wants to know.