I am having a problem with my engine not running right, it runs rich all the time, except when the car is decelerating. I think it might be a vacuum leak, but I'm not sure what exactly the vacuum is supposed to be at. I know mine is reading about 18 at idle, and if you give it gas it goes down of course. Is there a good way to test for leaks? If not a vacuum leak, then what else could cause it to run rich all the time?

Rob