I own a 2000 Toyota Sienna (130,000 mi). I now have a strong gas smell coming from the engine. It makes the interior smell as well, especially when turning on the fan. Toyota dealer couldn’t figure it out! A new gas cap seemed to help for a while. We are now on gas cap #3 and are about to give up on that. Any ideas out there?
I doubt if it is gas cap related.
I would start by following the fuel line from tank to engine. Make sure everything there is in good shape. After that I would look at the injection system.
Good Luck