Ok, so I did my research ( a bunch of searches) and I cant find the answers, please help. Ive got an 02 LB7 with a cat...... I want to do a full 4" system, but it sounds like I will throw codes for sure, true? If so, what are my choices? I would like to not put a blocker plate and fingerstick if possible. Anyone with this engine have feedback? Thanks in advance! BTW, if I have to add those 2 parts, about how much are they?