Quote Originally Posted by Remnant King View Post
I DID have a Check Engine Light, but that was the valve, which I replaced. How would I know if its a shot o2 sensor or vacuum leak?

Not sure if it's the exhaust, but there's a lot of loud and weird noises D:

I changed the fuel filter, and the pump IS making noise. Havent really looked into the lines for leaks, neither the o2 sensor. How would I check if the cat is clogged? I rarely ever heavy foot it unless I need to, and there's no way I heavy footing it as much as where it drops down THAT much. I go into the car this morning to warm it up. What started at 13 mpg, ended at 3.1 mpg by the time the car was done warming up...D:
Of course your MPG isn't good your sitting still. Also check your tire pressure.