poor gas mileage

Hi, I recently purchased a 2002 ford ranger edge with the 3.0L V6. I get around 12-15 mpg, so far I have replaced the plugs, wires, fuel filter, temp sensor, o2 sensors, MAF sensor, throttle positioning sensor and airfilter. The mileage still sucks and im still getting the error code or rich bank 1 and rich bank2 i believe the codes were PO172 and PO 175, could be wrong though.I justknow its the rich ones. Thanks

Have you checked your fuel injectors or fuel pump pressure or even a PCM problem. Before going through all the expense of replacing parts at random, you should have undergone a complete diagnostic test which is designed to pinpoint the problem.

well tomorrow im taking it in to get the fuel pressure checked, and possibly try and pinpoint which if any injectors are stuck. Also possible I'm told the timing could be off.

If you are getting only 12-15 mpg chances are the catalytic converter is plugged up. Does it get really hot? Do you have a rotten egg sulfur smell coming out the tail pipe? If you are getting that bad of mileage then the unburned fuel will have overtaxed the catylitic converter. A good way to diagnose a blocked cat is to put a vacuum gauge on the intake manifold. A reading of 17 inches or less indicates a plugged cat. Poor mileage will plug a cat and a plugged cat will cause poor mileage. Sort of a question of which came first, the chicken or the egg.

In this case, what come first is obvious, and fixing the cause is also obvious once you get the fuel system test. Jammed-open injectors sounds like a likely cause, but what do you do about the cat? Will it eventually burn away once you drive it from here to the beach a few times? ...or will a new cat be needed?

The only solution for a plugged cat is a new one. But, before replacing it run a vacuum guage reading for possible cause if it is less than 17 inches.

My f-250 gets poor mileage too, I'm considering purchasing a hybrid kit. I came across this video showing it in action. Judge for yourself,
http://www.advertisingagency1.com/water4gas.htm

Hope this helps.