Bad fuel mileage could be caused by a lot of things. The power steering pump could be the problem, but there's no way to tell. Since you already know it's bad, just replace it. When trying to fix a vague problem like this, it's best to start with the parts that you know are broken, and then do all the normal maintenance type stuff, like changing filters and checking the brakes.
If the O2 sensor went bad, you'd probably get an error code. The error codes are sometimes misleading, but if there's no error at all, I would assume that the sensor is OK.
The fuel filter, air filter and spark plugs should be changed regularly, so if you don't know how old they are, change them. But I wouldn't expect to get 6 MPG from it. |