Apparently the filter that you are refering to is located under the vehicle and is attached or is in proximity to the charcoal canister.
This filter is located inside of the CCV ( canister closed valve ).
The ccv has 2 vacuum lines,,1 is attached directly to the charcoal canister,,the other may be attached to the fuel filler pipe,,fuel tank vent,,fuel tank venting plumbing,,depending on application.
The approximate cost for replacement,,if necessary,,is about $ 400.00 ( U.S. )
On some units the filter can be disassembled for inspection,,on others it cannot.
On some units the canister and the ccv are sold as a complete assembly consisting of 2 seperate parts including hoses and clamps.
On other units the ccv is sold as a seperate part.
It is recommended that any hoses and clamps be replaced in conjunction with service or replacment.
( special note ) Unless the device has shown deterioration or has failed inspection test criteria and is operating nomally within given parameters replacment is not necessary.
No provision has been made for adjustment.
No i did not read this stuff out of a book,,i just surfed the web and checked all sorts of web sites for this info.
edmunds frowns on refering to other websites and expects its members to share info
maybe i can use just 1,,if they don't get too mad.
Source: http://www.hyundai forum dot com