Originally Posted by E350love
Ford E350 droning noise at 40 mph and up.What could cause this? Sound lowers when letting off the gas.Had driveline checked,new front tires,frontend alignment,muffler and resonator. Noise fills the van,sound like its coming from the exhaust. Has anyone had this problem? The noise is unbearable while driving.
The catalytic converters were removed two years ago.
You have answered your own question. The cats were removed. The drone in every van I've had with a lousy aftermarket exhaust or removed cats was unbearable, just as you describe, and it is worse on throttle, as you describe. When you let off the gas (and coast) it gets a lot quieter.
Put the cats back on. You aren't doing anything without them but poisoning yourself.