Which vacuum line needs to be removed to spray CRC GDI intake valve cleaner into for cleaning engine valve of carbon deposit?

I like to use the brake booster vacuum line, which is connected to the intake manifold, it is large enough to handle the cleaner. Check out the images (below). Let us know if you need anything else.

Hi Ken, are there any sensors on the way to the engine that may be affected by the cleaner if I use this brake booster vacuum line to clean engine? Are there other vacuum lines that is easier to access that I can also use? Thank you so much for your help.

You should be okay, but I have seen cleaners sometimes take out oxygen sensors but not all the time so be ready for that. I would use the brake booster hose, it works best.

Thank you Ken. Really appreciate for your advice.

You are welcome, let us know if you need anything else.