while inspecting trans issues i noticed this, don't remember hitting anything My opinion is it's not dramatic maybe I'm losing 20 15 or maybe as little as 10% of my exhaust capacity I've always noticed since I bought the truck 6 years ago that my mileage wasn't what it should be couldn't figure out why question is is this something to he addressed immediately or is this just something that I can leave alone and not worry about

 

Comes from the factory like that. Only way to get that outta there is to have a exhaust shop make you a new one

 

When ya push the exhaust down it also gets wider

Couple ideas to try:
1) You might do a pressure-check on your exhaust in front of the catalytic converter ...in case it's partially plugged up. On another forum I visit, a mechanic did an exhaust pressure check and the cat was pretty highly plugged.
2) Is your exhaust manifold cracked? When they crack a lot of times they crack in multiple places and even all around a pipe. That can throw off an O2 sensor causing your engine ECM to 'think' it's running in a way it's not. Worth checking
3) Intake manifold leaks (front/rear loose nuts)? Or vacuum leaks? What's the vacuum reading? Poor vacuum can lead to poor fuel usage.
4) Clean carbon and gunk out of the CCV, EGR, and IAC areas. Make sure they're working properly. Also clean throttle body.
5) Might be time for a compression check too.

 

if it comes from the factory like that then that would explain the lack of a mark or hit from an impact but I would have never thought that was a factory kind of thing unless somebody was ticked at a supervisor and took it out on my exhaust pipe

 

Nope they are all that way. They seam to get more restrictive the newer the model year on them. My 97 only has one dent in it

 

As ugly as it is, you can find this on other makes as well, all factory. Old and new, from header to tailpipe or anywhere in between. It can be done for clearance, or ease of assembly. Could be for flow. Could even be how it was bent at the factory. I wouldnt worry about it.

 

They are there for your emissions, helps the cat warm up faster

 

This is true...

 

I eat a lot of beans thus I qualify as an exhaust guru.........Oops, gotta go !

 

There is no EGR valve on later XJs because the dents at the header pipe create a hotter flow into the CAT. The engineers obviously discovered it was much cheaper to do it this way than to strap an EGR valve onto the exhaust manifold. The end result is the same so it passes emissions tests..