Hey Guy's, I 'm sure this question has been asked an 100 times or more but since I'm new I'll ask it anyway. I'm wanting to change the exhaust on my wifes 03 Ecurssion 6.0 diesel engine from the converter back. I have read that this will let the engine breath better and increase performance as well. There are alot of after market exhaust choices, have any of you guy's had any experience at doing this and has it improved performance etc? By the way does unpluging the egr help or hurt engine performance?