suv struggling to go uphill

What is your question?

so i purchased a lexus lx470 with 266k miles on it. Shop diagnosed and said both catalytic converters are clogged as suv lacks power and struggles to go up hill. i replaced both catalytic converters and it made no difference. changed spark plugs and fuel filters next but no luck. i do hear clicking noise from driver side which the exhaust shop repaired it but didn't do a good job and i hear it. Maybe intake manifold leak or vacuum leak? but i doubt it will cause lack of power?

What makes this problem better or worse?

lacks power going uphill

How long has your 2000 Lexus LX470 had this problem?

months