STOP STOP STOP!!!! I HAD THE SAME EXACT PROBLEM, i have the same truck, but a 4.0l. I had the code P0401 EGR flow insufficeint. I was told that people wrongly replace the EGR. i replaced the DPFE- Diferential Pressure Feedback- cost me $45 and only a few minutes of my time. it is located on the left side of motor above the power steering resevior. it say HI and REV on it with 2 tubes descending from the bottom, disconnect the wires and hoses, re install new DPFE, and disconnect the NEG battery cable for 15 secs minimum, and you should be good to go, my light hasn't come on yet. | 
