Hi all. I purchased a used 2013 ridgeline sport with 25 k. One day over the winter, it didn't fill up all the way. I thought t was user error. 3 months later and it still only gets about 18 gallons and the range after full up is 299-307. There is no check engine light. Some people say to clean out then breather tube for the tank but I have no clue where that is because the diagrams look like Greek to me. Pictures would help! Anyone know what this could be? Honda dealership had never heard of it. My mechanic had never heard of t. Clearly, this is real and I saw it happens to other cars. Could it be the level sensor in the tank? That would stink, since I assume someone would have to drop the tank to get to that. I'm very bummed that I have a problem like this after 5k miles. (30k total). Maybe I overfilled it once or twice? And if that were the case and something happened with carbon canister, wouldn't that make the check engine light go on? Help.