Percolating gas into a hot manifold or any gas drip on a hot surface will set up a good stench in your garage that will last awhile.  And it doesn’t take but a few drops on something really hot.  Normal exhaust odor is not as intense or offensive to me but can take a couple of days to dissipate in my garage to where I can no longer smell it.  I guess before catalytic converters we were so use to exhaust odors that we never gave it a second thought.
	
		
			
		
		
	
				
			 
				 
 
		 
 
		 
 
		 
 
		
 
 
		
 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		 
 
		














