Hey guys, have a quick question. Just finished installing my AEM boost gauge today and used 7/64'' vacuum lines. I believe AEM typically sends 1/8'' lines with their boost gauges but I bought it off someone used so I did not get those. After installation, I turned on my car and it's reading -20... My accessport is around -8 which I believe is normal for the car at idle (I think). The cars own vacuum line that I splice into (and T-jointed) is a good amount bigger than 7/64''. Is the reason that I'm getting this weird reading because of the change in vacuum line size at the T-joint? I attached a picture to help understand, in case my writing is not clear. Thanks in advance

 

That's normal the boost gauge reads vacuum in inhg vs Cobb accessport that reads in psi. Use a conversion to translate it.

 

Perfect! They are the same. Thanks

 

Your reading is good man. But that t fitting looks way too big for the sensor line.
I used 1/8 x 1/4 x 1/4 from autozone and it fits perfectly.

I think as long as all the lines Snug fit, you will be good.

 

No problem. It's a common mistake that people make on their first boost gauge install.