"My work truck, a 2014 Ford F-650 V-10 with only 20k miles started running very poorly recently. The engine was running roughly, the CEL was almost always on, there was an ammonia smell from the exhaust, plus it would emit a cloud of white smoke that smelled like unburned gasoline a few times a day. Power was way down. The exhaust emmisions even caught on fire TWICE! It was into the Ford dealership twice where they changed the O2 sensor, the catalytic converter and the air filter, all to no avail at all. Yesterday I decided to buy a bottle of Lucas Oil Deep Clean Fuel System Cleaner. I put in the bottle this morning, then filled the gas tank and started my work day. Not only are ALL of the abovementioned symptoms completely now gone, the truck is getting about 1 mpg better gas mileage, which is huge, since it was getting 3 mpg before. Thank you Lucas! Can't wait to tell my employers how "I" fixed their truck!" -Michael M.