Clean or replace cats?

[heyjewel]

I had to pull my exhaust system to replace a $3.00 seal on my 2001 Getrag.
Now that it's out, I'm wondering if I should try to clean or replace the catalytic converters or just leave somewhat well enough alone? Reason - car and cats have 200K on them. I rebuilt the engine and it 'seems' like it has less power than before and it is definitely getting fewer mpgs. Both could be cat-caused?
Cleaning - At youtube auto university there are videos about cleaning cats. Scotty Kilmer takes a cat and puts it in a bucket of soapy water overnight.
My cats are permanently attached to the manifold pipe so either cleaning or replacing would require me to cut them from the pipe and then reattach with clamps.
Does anyone have a comment on this job thinking?

 

[heyjewel]

Or maybe, with the exhaust off and balanced just right with the cats at the bottom, I can pour the detergent solution into the exhaust at the manifold flanges and have it sit just right in the cats to clean em? Agitate it once in a while.

 

[Broseph]

Sorry friend. You're doing half measure tactics to fix the issue. Problem solved once and for all? You need to do diagnostics to determine the real cause - is it spark, timing, fuel? Do you have any fuel readings?

What is "rebuilt"? Was timing done? While it would create noticeable issues if timing is really far off, minor timing change would affect power without a noticeable difference in daily driving.

When you fix something old, often something that was marginal becomes an issue.

And btw, cat "cleaning" is a proven myth, it's a bandaid at best. If that's your problem, you need new cats on top of figuring out what caused the previous cats to clog (bad COP, running lean etc.)