Over the last year, my 2013 Pilot has started losing gas mileage. It is currently down to about 15/18 mpg. It has about 83000. Recently, there has been a rattle coming from the bottom of the car after the car warms up, when I apply the gas. Before it is completely hot, it almost feels like a grind or growl but is very faint (to where my hubby doesn’t notice it because he rarely drives my car). When the gas mileage started to decline, I had all the spark plugs changed and I have done all required maintenance throughout the life of the car. I don’t want to go changing stuff willy nilly until it’s works, but right now, this gas mileage is insane. BTW, this not an AWD car. It is a basic Pilot. Thanks for any advice!