My 1999 2.5L V6 Contour is fun to drive, but I have suffered from poor gas milage (about 17MPG no matter if it is highway or city driving). Anyway, the check engine light came on a few months back. it was when I was doing about 45 minutes of highway driving. After some shorting in-city driving, the light went off. As soon as I hit the highway for over 30 minutes, the light would come back on... Repeat a few times.

Anyway, I was at a point where I couldn't do anything about getting it fixed, and now the light stays on all of the time. I just started a new job and want to get this fixed, but I am not 100% sure what the problem is. I stopped by AdvanceAuto Parts and had them read the codes.

Here are the codes
P1131 - Fuel Air Metering
P1151 - Fuel Air Metering
P0171 - Running too lean Bank 1
P0174 - Running too lean Bank 2

Does this mean oxy sensors need replacing, or could it be a hose? Something else? Should I try and fix it myself? I have done a lot of basic car work such as oil changes, brakes, alternators (not on my Contour), spark plugs, plug wires, and such, but I always had someone to help me the first time. Should I fork over the big bucks and have a shop do it?

Thanks all!

Nick