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			@Hooker:  
recessing the O2 sensors pulls them out of the exhaust stream a bit.  the result is partial vacuum at the sensor head; it will read lower HC & NO2.  it works.  in fact, some aftermarket companies sell O2 bung extesions that accomplish this task. 
 
@stateofidleness: 
the inlets on your aftermarket muffler need to be 2".
		 
		
		
		
		
		
		
			
		
		
		
		
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