im running really rich seems like im burning thru a tank of gas in less then 300 miles.... where normally im getting about 400-450mpg per tank... 92 3.0 190k, 3.48 gear.. auto supercab ive put 3 different gas gauges in it thinking that was problem... truck exhuast doesnt smell rich.... new air filter, plugs/wires about 1k ago oil change in 250miles (due soon), i know they switched to "winter blend" but theres no reason to lose 100-150mpg tank wise just due to that fact... pvc valve good... and also common places for this motor to leak/burn coolant... not burning in exhuast but over about 2k miles overflow goes bone dry... and using ABOUT 1/2 quart of oil in 5k miles... any advice on cleaning options... or possible air leaks??? like lower intake??