Nissan Infiniti Q45 ECU Up for sale is a Working, in excellent condition 1991-92 Infinity Q45 Engine fuel control module. Part number-- A18A21P66K , This is a used, original Infinity/Nissan remanufactured ECU. The K indicated it's a remanufactured unit. Mainly used for testing purposes, probably has less than 30 miles on it. For an early 92, May fit other models/years, Up to the buyer to find this out. As always your best bet is to match the part number to the one on your original ECU. These units have been NLA for quite a while now, and are not at all easy to find, at any price much less as fair as this. Price this new or rebuilt, and you will see this is a fantastic deal. Comes with a 30 day functionality guarantee. A faulty ECU is one of the most common no start or random stalling & low power problems with these cars. These can also cause issues with erroneous check engine lights as well as emission control malfunctions & cold or hot start problems. If your car does not have these issues but you intend to keep it a while, I recommend our customers keep an extra ECU in the trunk. These units now have to be special ordered from most dealers new for big $$ (often times over $1000!), and you can never find the right one when you need one. Even now finding a good one second hand is getting to be quite difficult as these cars get older.