I'm going crazy because every year I take my truck to get inspected they say its running lean because I have a vacuum hose leak. Every year for the past 3 years they have changed and fixed it. It's always been a short one towards the front of the motor that's somehow wore a hole in it. I just got back this year and now they its another one and they have to find it. I usually do all my own mechanic work so I told the guy I would just do it myself this time. I just want to know if anyone has a diagram or where I can find one so I can find and check them all and probably just replace them all. I'm fed up with every time they hook up to the obd the same running lean code pops up. Maybe some of you guys know that its just a particular hose that's the problem and would let me know. Any help would be greatly appreciated. Oh its on a 99 4x4 4.2 F-150 straight drive 5 speed.

 

What's the code?

I have not had the worn PCV hose issue, but I did have a P0174 that grew into an intake manifold gasket swap out.

Even then, I only dealt with that because my crank position sensor magnet broke and the truck stumbled like crazy...so, it was more than just that gasket at work.