would EVAP codes = bad gas mileage??

[01t4rnr]

So i have the dreaded EVAP codes , think it was PO446 and another one cant remember exactly (P0440 i think)but ever since ive just unplugged the bulbs in the dash- out of sight out of mind. Truck runs fine, no skipping or power loss that i can tell but im getting terrible mileage (around 12-14 mpg) I also have a strong smell when you first crank it up from the exhaust, guess its kind of like a gas smell but no smoke. Im thinking its the front o2 sensor or the cat is clogged which i dont think is likely. Some say charcoal canister but that wouldnt affect mileage any at all would it?Isnt there a way to check the sensor with a meter or something? I know its well over $100 for the front sensor and i hate to pay Toyota to look it over . i know the 285's kill the mileage some but i should at least be getting 15 or better . I dont really care about the lights in the dash, i just want my mileage back up. Any help is greatly appreciated

 

[01t4rnr]

and the truck has 105K on the clock if that helps. new muffler, plugs, air filter, and fuel filter

 

[rdgt4r]

Seafoam it! 285's with what gearing and all? What was the MPG's before and with the start of the 285's?

 

[01t4rnr]

when i first bought it it had 8x,000 miles on it with stock 265's & it was averaging 18 mpg. I remember getting over 300 miles to a tank. Now i dont ever fill it up b/c it sucks it down so fast but last time i checked it was getting 13-14 at best driving it easy to take my son back and forth to school. No traffic just country roads and a couple red lights in town. But like i said i can smell it strong but dont see any gas leaks or anything so in my mind its the front sensor but again just my guess. might try cleaning the MAF sensor this weekend to see if it helps any.