Quote:
Originally Posted by Tinker
Modern cars can be tested with a vacuum gauge.
|
But, while you can see smoke, you can't see vacuum! If you have a leak in the evap system, injecting smoke will pinpoint the leak. Whereas if you merely watch a vacuum gauge to see if it drops you still have no idea where the leak is. Plus, if you're hunting an exhaust leak it's pretty hard to pull a vacuum on the exhaust system! But if you inject smoke into the tailpipe any leaks soon become obvious.