I wouldn't say my car doesn't have power at lower rpm...it's just not "peppy"

At high rpm, I can feel that the car is not "moving"...I can feel that there's no (or very little power)...

Could this be a clog in the pre-catalytic converters?

Question: How do I check if they are clogged? It seems that the bolts holding the pre-cats to the headers are quite difficult to remove (there is some rust on them)...

If I remove the pre-cats and look at them to determine if they are clogged, I don't think I'll be able to put them back if they're not clogged without getting some new parts, such as new bolts/nuts and new seals?

What do you think?

Thanks.