Hey guys yesterday the fan stopped working in my 87 2.8 and it overheated a bit. When I got the fan working again it had no power and its running really rough. When I say no power it will barely go over 35 and takes a long time to get there and its shifting weird. I'v done some research and it kinda sounds like a clogged cat but it isn't running hot and I disconnected the o2 sensor and there was no change. Any ideas?

 

Yes it could be the cat, easiest way to check it is to loosen the y pipe & test drive it.
Other things that cause low power is low fuel pressure & ignition timing that doesn't advance as you rev it.