I'm writing this more of an FYI help to some of you that run into what I ran into last night. And to prevent some of the problems caused by my car's previous owner.
Lesson Summary: don't mount your exhaust too low, don't cross thread bolts, ***always use some type of anti-seize on bolts for your exaust ... and brakes, and anything else that gets hot as hell or rusts a lot***, plan ahead... sometimes you need a special tool or parts that you didn't intend on.
When I bought my mustang it had Pypes hi flow cats on it. Up until now it was too cold to get the initiative to either clean out my garage or want to work outside. It has a bassani offroad x-pipe which is modular in that you can drop sections from it and put in cats or run it cat-less.
Well, this seemed to be an easy task but my lack of experience removing this particular exhaust setup and some corrosion made this take forever.
my particular pipes overlap instead of having flanges. I prefer flanges. Combined with a little rust, these overlapped pipes can be hard to separate. So I built something to help.
I used some angle Iron, some exhaust clamps a buddy left when I welded his exhaust, some all thread, washers, and two nuts. it's ugly but works great. you can set it up to separate the pipes by positioning the nut to push the two clamps apart while turning the nut counter clockwise. You can also pull the pipes together by putting the nut on as shown and turning the nut clockwise. I thought I was so ingenious until i found this today.
Summit Racing® E-Z Pull Exhaust Pipe Separator Tools SUM-900652 - SummitRacing.com
that one doesn't fit 2.5" pipes but they make one that does for $70. who cares, you can make one yourself now for less than $10.
Why did I remove the cats? well, I live in OK and we don't have inspections. And I date a hippie that I love to spite. And... my car wasn't running right. The tune for my car is set up for no cats. that may have been the problem but this might have been also...
Finally, the night could have been much worse but I got a little lucky. to get room for separating my pipes, I removed my pipes from the headers. The previous owner said there was a stripped bolt on the exhaust causing a leak. I had assumed the stripped bolt was on one of the clamps which would be an easy fix. I was wrong. It was on the header. The guy had cross-threaded the nut. Luckily, he didnt get it all the way on so when it broke off, I had just enough thread to still get my nut on after i cleaned up the threads. I will fix this later with new long tubes, but for now this works...
Oh, one last lesson, Pypes exaust clamps have a shaped piece that keeps the pipe from bulging and leaking where the clamp comes together. This piece is ceramic so it will deteriorate over time. I now have two leaking clamps that I have to replace because the pieces fell apart when i loosened my exaust.
I hope this helps a few of you.
I can write a how to on building the exaust tool i made. I feel it is pretty straightforward if you have a welder and a few other tools and look at the picture.