Thank you for taking my question. A couple of years ago we had to have the sensors in the gas tank replaced in our 2009 Hyundai Santa Fe. Ever since then, if we fill it over half a tank, it smells like gas fumes in the car. We did take it back, they said they found one tiny place where the tank did not have a good seal… The tank has to be opened up to replace sensors… this problem was supposedly fixed. It still smells, and I only filled half a tank full. That was just set up this question. The other day when I turned on the ignition the engine did turn over and the car started but there was a clattering noise at the very beginning. This happened several times. The gas gauge read low… I filled it to half a tank… And the noise disappeared. Any idea why there was clattering sound when I turned on the ignition, this was not like a clicking noise like when a battery is dead, and the noise disappearing when I filled the tank to half full. I look forward to your answers. And thank you for your program! 
Debbie Smith Weatherford Texas. PS. This has been a wonderful car all the 10 years we have had it with great get up and go. It is at about 150,000 miles now… And we have always had dealership maintenance done when needed.
Since no one else will respond to your question, I will.
The people who last messed with your fuel system messed up.
You shouldn’t smell a gas odor from a 2009 Santa Fe.
Tester
The evap systems on modern cars like yours are pretty complicated and by the posts we get here there’s a lot than can go wrong. This is sort of like if you have a leak in you bicycle tire, the bike shop fixes it, but it still leaks. Nothing else to do but take it back to the shop and have them fix the remaining leak(s).
Clattering noises when the engine is first started, especially cold starts, make me think the engine oil level may be low. That’s the first check, the oil level on the dipstick is?