Does anyone know anything about this: When I start my car a huge puff of black smoke comes out my tailpipe. Also sometimes throughout idling. It even like leaked gas one time, out the tailpipe and the muffler (at least I think it was gas, it had blue on top of it)? My exhaust smells very strong and suffocates you from far distances. It smells really bad. Does anyone know what's goin on here? NOTE: Sometimes I let my battery almost die out and then I start it up.