I am still getting horrible mileage i replaced the 02 sensor with ac delco i have new spark plugs and generic new spark plug wires. Is there anything else that could cause this. also there is a rip in one of the tubes that goes to the evap canister would that affect anything? for all and any inpuit

Yes, replace the torn vacuum line going to the evap canistor. It recycles fuel vapors.

When'* the last time the fuel filter was replaced?

How much does this affect gas mileage? Because mine is bad, but I don't think it is bad enough for a fried O2. BTW, I am getting 17 MPG mixed driving conditions.

Always a good idea to replace fuel filters regularly (every 30,000 miles or 2 years) for many reasons. 1 A plugged filter is hard on the pump, 2 A plugged filter will deteriorate your MPG and performance, 3 A filter that stays on too long does not like to come off....rusts on.

As for your problem, I would definately clean the MAF sensor just because it is easy and free! Also fix your EVAP line leak <<< A MUST! Just for the simple reason that you know its a problem and you know it will hurt mileage.

Yeah i figured the torn line went to the fuel so i did a temporary patch of it. I mean im getting horrible mileage i haveto put in 10 dollars every other day to keep myself away from the Empty line. My gas guage fluctuates weridly at times and idk if this is normal but i can drive around for a long time under the Empty line.I am not sure how long though im to chicken to see how far i can go before it stalls.

I never replaced the fuel filter can that cause horrible mileage? I would figure it would just be aperformance thing instead of mileage but i guess it makes sense to have cleaner gas to burn more efficently.

Check your fuel pressure regulator also.

It sounds like you may have a bad sending unit in the fuel tank giving you false readings...which won't affect your fuel mileage but will trick a person into thingking they are getting bad mileage. If you actually test your MPG the right way, you don't need a fuel guage.

And yes a plugged filter can affect mileage because it can reduce fuel pressure under heavy load conditions---this results in an unsaticfactory spray pattern from the injectors which results in poor combustion charicteristics---which results in lack of power and a poor burn rate of the fuel.

what is the right way to test your fuel milage i just go by what i pit in and the trip meter. How do i test my fuel pressure will a code reader give me this useful info im thinking of buying one

Where should i buy a sending unit from and is it a large job to replace the unit? also to save me time and money is there anyway to test if its good or bad?