I bit the bullet Monday and bought a 91.  It was picked up today in Maryland. Delivery is scheduled for Friday.  
 
	 
 
	My question concerns the Tech 1 Diagnostic Computer.  Are they useful?  What is an alternate, Snap-On?
 
	  I received the tech manual today and have made it to the driveability and emissions section.  I will have many questions in the future.
 
	 
 
	Jim