Originally Posted by msa4x4
whats a lean condition? and my cats are still on it will make that sound when its just sitting turned off
lean= too much air or not enough fuel in the A/F mixture
when its shut off and it makes a popping noise is just the pipes cooling down. nothing to worry about at all. it does the same with every stock exhaust system that i've seen, its just more noticeable when its on both sides instead of just the passenger side.