2002 mustang gt fuel cap light on?

So I have a 2002 mustang gt. I purchased it about 2 months ago, and about 3 weeks ago the fule cap light went on. I called my mechanic to look at it, because the light wouldn't come off. I tired many times to close it, but the light was still on. I asked around and they told me it might be a sensor. So my mechanic came and looked at the car. He said nothing was wrong, just change the fuel cap. So I bought an original cap off a ford dealership, and changed it. I unplugged the batter and plugged it back in, and the light went away. This morning I was coming home from work and the check fuel cap light turned on again at the same spot, around the same time, and same day it turned on the first time. What a coincidence I know. So I just unplugged the battery again and plugged it back in, and the light turned off. Should I be concerned about it? Should I take the car to get checked? Any advice would be greatly appreciated, thank you.

With the high price of gas these days it is no wonder locking gas caps have become popular again… Fuel Doors · Wheel Accessories · Grilles · Window Tint & Light Tint… 99-04 Mustang Fuel Delivery Parts º Motorcraft Locking Fuel Cap (99-04 GT, V6) … Mustang Fitment: 1999, 2000, 2001, 2002, 2003, 2004 Details >> …

You are more than likely not tightening the cap enough. Make sure when you tighten the cap you hear it click at least 3 times. If that does not solve the problem you may be getting a false positive from the sensor. In that case the sensor will need to be replaced.

Also, there's a hose that goes from the top of the fuel tank all the way forward to the engine bay, & they have been know to age & crack.