What the Libra zodiac sign is all about: Libra is the seventh of the 12 zodiac signs, which begins its cycle in early fall every year during Libra seasonâwhich falls around September 23-October 22.
How it works. This schematic shows the component parts of a typical leak-down tester. The gauge on the right is held at a standard pressure by adjusting the pressure regulator while the gauge on the left shows an example reading of 85-or 15% leakage.
A test pipe replaces the cat, and has no restrictions like the cat does. The purpose of the test pipe is so you can have a full exhaust without having a cat causing exhaust restrictions. A test pipe won't pass smog, many people keep a cat around and switch it with the test pipe only on smog day. #4. BogusSVO, May 25, 2012 #5. A test pipe is just what the name implies, it is only for testing pourposes. It is used to check for a clogged cat.