Scheduled to go in tommorow morning to the local exhaust shop. Wondering if I put a 4" turbo back and leave the CAT if I will have any problems with throwing codes? If so, will a 4" CAT back make that big a difference in the EGT's? Scheduled for Tuesday to have a BD XMonitor installed as well. Any suggestions or thoughts?

How did it go with your Exhaust install ,which setup did you finally go with and what did you notice afterwords?