1nzfe and 2nzfe same air intake?

[Yaross]

I just found out today the following similarities of 1NZ-FE (1.5L) with my 2NZ-FE (1.3L) engine:

Throttle Body - same part number (22030-21030)
Air Cleaner Rubber hose - same part number (17880-21091)
Air Filter Element - same part number (17801-21050)
Air Cleaner inlet pipe - same part number (17751-21160)

The only difference in the air intake is that 1.5L has additional carbon/charcoal filter fitted inside the top cover of the air cleaner. (The intake manifold is also not the same part number).

My questions:

1. If they have same part number, does it mean they are one and the same?
2. If the answer to no. 1 is "yes", does it mean I already have an oversize air filter/cleaner for my 1.3L engine?
3. If the answer to no. 1 and 2 is "yes", does it mean that other than getting better sounding engine, I will not gain anything if I change my air intake to SRI?

I appreciate all your expert opinion.

P.S. I would also like to see some feedback from those people who has same engine as mine but and already modified their air intake.

Thanks a lot guys!!!