Vehicle will not get enough power to climb a small hill?

Can you confirm the car only has 16k on it? Have you tried down shifting the transmission manually? I would say you need to check the catalytic converter, but I have not seen this part go bad with that many miles on it. Here is a guide to go over as well to help see what can cause this problem:

https://www.2carpros.com/articles/engine-has-low-power-output

Also, can you please check the air filter? Here is how in the images below. Check out the images (below). Let us know how it goes.