Hi guys. I joined this forum about a year ago but have never posted. Just a quick question. I searched but found some conflicting info. I have an 02 3.9l and want to know what the stock exhaust diameter is. The tail pipe is 2.5 inch, but is it the same diameter from the cat back? I kept seeing posts about it being 2.25, but my tailpipe is definitely 2.5. Thanks.

 

from the cat all the way back it is 2.5

 

is it the same back to 99?

 

affirmative