2011 sonata fuel filter location
It maybe part of fuel pump assembly. Good news, should be an access panel in the trunk. A lot of makes and models that I've seen, if returnless fuel system, meaning only one fuel line from the tank to the front, on most of those, the fuel filter and fuel pressure regulator are part of the pump assembly. The info I looked at was for 6th generation YF Hyundai sonata. I found some info on this site, www.hsguide.net I am not a Hyundai expert.
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