Where is the cabin air filter in my 2013 f150 stx, it smells funky in my pickup when I turn on the fan.

 

No need to double post and welcome to the forum, your truck does not have a cabin air filter. There is a procedure to alleviate the smell but requires specialized equipment and chemicals that usually only the dealer has, there may be some outside a/c shops that can do it as well, just have to call around and find who can help, it involves cleaning the evaporator core.
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For your future posting consider .....

HINT/TIP: You'll find posting in thesection more helpful/appropriate than General F150 Discussion posts.
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And as Rnlcomp noted ... The gen' 12 F-150s do not have a cabin air filter nor the capability of retro-fitting one.

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