horrible gas mileage

[drowndindreams]

ok so, my problem is this.

a while ago i realized my fuel pump went out (fathers words). so my fuel gauge is all screwed up.

now im seeing that if i fill up a gallon (rarely) instead of getting about 15, i barely get 10. i have no lift, stock rims and tires.

so now i read my fuel buy the odometer.

a while ago, i filled up and expected 300 miles plus, it died at 245 miles.

something has to be wrong, we recently replaced the fuel filter.

any thoughts please?

 

[cmcarr85]

Definitely something wrong...... Check tire pressure, spark plugs, wires, check engine light on?

Driving different? Could temperature in the air make a different?

Good luck

 

["350Vortec"]

Fuel Pump faulty? I had a faulty one put in mine and it was making sounds and i was puttin in $20 bucks every other day.

 

[drowndindreams]

my best guess is the pump its making some weird noises other than the annoying buzz it already makes

 

[bsamoul]

I've always wondered if my truck had this same issue. I replaced my plugs/wires, fuel pump and fuel filter all within a year but I still get about 11 mpg. My SES has been on saying that one of my cats is bad, so I have replaced my o2 sensors but the light remains lit. Could that cat be dragging my mileage down? I've read people's posts on here saying they get like 15, and I've never had that. If anyone could possibly have an answer to this, that would be most awesome.

 

["350Vortec"]

Most likely if your pump is whining, or making loud sounds, 1. its on its way out, and 2. its not running to its full capacity and hindering your performance and gas mileage. So bring it by a shop to have it looked at.

 

[ravingmadman]

Yes, if your cats are bad, that will affect your mileage, especially if they are causing a blockage. Exhaust gases exit the engine, go out the exhaust manifold, go through the cat(s) and get burned up, go through the muffler, and out the tail pipe. If there is significant restriction at any point, then your engine has to work to push the exhaust out of the engine, which will kill your mileage, performance, everything.

This is why you can feel an increase in power when you put a larger exhaust pipe, or long tube headers, or performance mufflers on your rig. Anything that helps air get in easier, and exhaust get out easier will add lots of power.

Also, you won't be able to get your Hoe licensed, as it will fail emissions next time you need to get your tabs replaced. Head's up...


---------- Post added at 12:23 PM ---------- Previous post was at 12:19 PM ----------

Long tube headers, dual exhaust, hi-flow cats, lake pipes ftw. I wish....