Bad Injectors

[Back-N-Black 76]

My dad just bought a 2007 5.9 and only had it a week. i checked the oil and notice that is was over full, a little thin, and smelled a little like fuel. I took it to the Dodge place and got them to check it out. Turns out 3 of the injectors were bad and fuel was getting into the oil. Dad was pretty upset and I hated it for him because this is his first experience with diesels and Cummins. Luckily it is going to be covered under warranty! But come to find out the previous owner had an Edge Juice w/ Attitude on it, with stock exhaust and intake. Could that have caused some of the problem?