P0171...Can't find vacuum leaks

[RJ255]

So I got the famous P0171 code, but I can't find any leaks so far in the vacuum lines. I check the blue tee, and turbo inlet (looks worn but not torn, sprayed soapy water on it...no bubbles). I had a loose throttle body clamp which i tightened, code still came back. Stock airbox seems fine, nothing loose. I will inspect some more when I have the chance.

 

Now I noticed there is a leak somewhere in the pre-catalytic exhaust system, I could smell the fumes and I hear a bit of a rumble, just haven't located the exact location. Could this be the cause of my code? Not sure if the location of the O2 sensor would have anything to do with this.

 

If not, maybe a new MAF or O2 sensor is in order? Previous owner installed a new O2 sensor so I'd probably hold off on that route.

 

Apologies on any obvious questions here, and for the fact that there are a thousand P0171 threads already (I know I searched).

[BX77]

I found mine on the hose the runs from the Blue Tee to the front of the car, It's hard to see at first and bitch to get to

[bkv348]

Clean your maf sensor?

[RJ255]

Clean your maf sensor?

 

Oh forgot to mention that I cleaned it already.

[gimpydingo]

Just to rule out leaks, for a quick check (this is how I found my turbo inlet tear) pop the smaller line from the BOV/BPV and blow into it with lung power. If that yields no results, hook up an air compressor to that line and pressurize the system to 5 or so PSI. The other thing is a boost tester as well, which I made for a few $$$ from PVC.