Gas milage?

you might be losing because of a tighter engine. if you have an oil leak take it back an dhave them fix it.

i did the engine rebuild myself and im getting about 300 miles to the tank i looked up how much i was suppsed to get and it said 422 when stock and i have a cold air intake and high proformance spark plugs that ive been using since i bought the car and i was getting almost 500 miles to the tank. the spark plugs are fairly new less then 2,000 miles on them. could i possibly be loosing that much mileage bc of the cold?

cold weather will change the mileage significan'tly

ok thank you for the info i never realized how much i lost in the cold before till now

well it should imporve as the engine breaks in as it will get looser which is normal. as long as you dind't screw anything up while putting the engine together you shoud be ok. that owuld be the only other reason for lower fule mileage.

my car finally thru 2 codes p0455 and p1448

both of those are evap valve open and gross leak. check for a blocked or hose left off or blocked giong to teh evap cannister purge . Make sure your gas cap is tight it should click at least 3 times as that can causeit as well. it cold be a bad valve as well, that would be acause for lower fuel economy

ok sounds good thanks