#5 is the rear cylinder on the driver side.
The injectors are supplied battery voltage when the ignition in the START or RUN position. The ECM supplies a pulsed ground to open them. If you don't have a bi-directional scan tool, it would be worthwhile to pay a shop to run the injector tests for you rather than spend a bunch of money on a guess, or run the risk of damaging the ECM.
The thread below explains how to replace the injectors however, these injectors rarely fail. What usually happens is the poppet valve gets clogged and won't squirt fuel. You can purchase the injectors separately, (comes with the poppet) for just under $100 each OR, you can upgrade to the MFI system which totally eliminates the poppet valves and relocates the injectors to the intake ports using all new injectors, and fuel pressure regulator, for just under $200. In this thread, this is what's being done:
http://www.automotiveforums.com/vbul...d.php?t=559014