exhaust measurements, different?

hey guys i was looking into buying one of them super 40s and i wondered to myself, do i have 2.25 or 2.5 inch pipes...

so i measured with a micrometer callipers and measured 3" in from the cat and around 2.3 to 2.5 (the output metal was tapered) on the rear side.

what sized super 40 should i get the 3" and get some new rear tubing, or the 2.5 and do something with the cat tube

come on guys i need help

You have 2 1/4" size pipe stock on 90% all xj's. Some early 4 cylinders had 2". Get the 2 1/4" muffler and if you want to have a larger diameter tail pipe made the Flowmaster is more than able to do it. You will need to have a pipe made up anyway to make up the length difference betwen the muffler and tail pipe. If staying stock size it is the ideal time to replace the tail pipe as it retails under $3o. No room for 3" without some serious mods.

your caliper is measuring the outside diameter of the tubing and this changes as some of it is flared to mate up with the next piece.

what year is your jeep and is it the stock muffler?

ID (inner diameter) of piping differs from OD (outer diameter). Measurements on mufflers and such is the ID.