Painfully close to finding vacuum leak which I can hear but not find

Got a code yesterday. P0171.

If I blow into the vacuum line for my boost sensor into the supercharger, I can hear the air being expelled. However, I cannot for the life of me find where it is being expelled from.

I am blowing vape smoke through the boost vacuum line but I don’t see it exiting anywhere.

Lastly, I can (sometimes; it’s intermittent) hear a hissing leak.

I know it’s near the intake manifold surface. I just don’t know where exactly.

Please help!

 

What gen supercharger?

 

And they want to ban these things

 

Lol. I see the humor, too, but I am desperate.

1997 Tacoma 2.7L 4x4
70mm pulley Magnuson
Stock ECU

MAF reading at ~3.0 g/s @ idle

Rear O2 stable at 0.7

Front O2 bouncing around a lot obviously but between 0.1 and 0.8

Wideband O2 seems to finally read stoich at idle but goes lean with any throttle

Long term fuel trim around 25

Short term fuel trim highly variable obviously but generally positive between 2 and 8.

Total fuel trim (if we take the sum) > 30

Tested the brake booster; it is not the source of the leak.

Tested the vacuum line from throttle body to EVAP; it is not the source of the leak.

Fuel rail pressure ~35 PSI.

When I blow into the boost vacuum line, I can hear air. Maybe I am just stupid but it sounds to me like it is exiting somewhere. Problem is that I don’t know where it is exiting or if I am simply hearing the air move within the supercharger . . .

 

The most recent work I did was changing the spark plugs and coil packs. I torqued the plugs to 14 ft. pounds. The plugs are helenium’s gapped at 0.042.

Lately, my wideband O2 sensor has seemed to wander more than usual. I am running 92 octane.

When I got back from a trip into the city yesterday, that is when I noticed the engine light and, if I am not wrong, I think I may have experienced a couple of small misfires; though, that could have just been my foot moving due to bumpy road.

 

I have a funny feeling this leak is between the supercharger and cylinder head - the mating surface.

I think that is why I can hear the leak but cannot feel it since the supercharger makes reaching things so hard.

 

Use a can of starter fluid and if the rpm’s go up where u spray that’s the area of the leak,
Easy

 

I found it.

the leak is in the corner of the air intake on the cylinder head near the power steering, the front of the intake. I am going to try torquing everything down.

 

That's so funny, I did that to tune the airflow on my PC

 

Maybe I should just let this thread die but I ended up buying a smoke machine.

I noticed smoke coming out from what looked like beneath the second fuel injector (cylinder 2).

Before I had the smoke machine, spraying carb cleaner by the front of the manifold (cylinder 1) resulted in noticeable RPM change.

@1997tacomav6 I know spraying for leaks is usually easy but maneuvering around the supercharger with a big can was actually a little tough.

In conclusion, I guess the issue is probably my intake manifold gasket and possibly the injector seals.