P0171- I think I need to replace vacuum hoses.

<Bump> on the P0171 code. Here is some information on how MAF sensors work, and how they fail.
Not sure if this will help in your case, but it might give you some ideas on where to look for possible faults.

Mass Air flow Sensor (MAF): how it works, symptoms, problems, testing

Good luck!

 

There is a schematic vacuum diagram under the hood.

Your typical mechanic (or auto parts store person) reading a P0171 will tell you that you need a new upstream O2 sensor. That is, of course, not necessarily the case, but frequently is. In other words, the normal assumption isn't a vacuum leak, but a bad sensor. Both assumptions are ... well, assumptions.

Do you have a scantool with which you can get live data from your O2 sensors? P0171 just means that the upstream O2 sensor is getting abnormally low (lean = too much air) readings. It can come from vacuum leaks or a bad sensor. But it starts with getting some data.

And as far as vacuum leaks go, don't count out the intake manifold.

 

There's nothing wring with an O2 sensor reading of .86, but it's not static. You would need to be able to graph it. The O2 sensor should be constantly bouncing up and down between about .1V and .9V

I tried to post a pic, but it won't work. See: OXYGEN SENSORS: HOW TO DIAGNOSE & REPLACE