I got my jegs catalog in the mail today and since I was going to make a costom exhaust system I wanted to know the outlet pipe from the header because i was planning to make the piping 2.50" all the way around and I was going to buy a high-flow catalytic converter from magnaflow would I need to put the O2 scencor from the stock catalytic converter in the new one please help me i am new to costom making stuff