it is the back cylinder (closest to the firewall) on the passenger side. If you are diagnosing a missfire code on cyl number 4, you probably have a bad ignition coil on that cylinder
Cylinder number 4 is located on the Passenger side near the firewall. (Back of the engine)
If you are facing the front of the engine 1 is the cylinder closes to you on the left then 2 behind that then 3 and after that it is 4, on the right side it goes 5,6,7,8.
4 - 8 3 - 7 2 - 6 1 - 5 front
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front
firewall 5 - 10 4 - 9 3 - 8 2 - 7 1 - 6 front
Cylinder #4, is located on the Pass. Side near the fire wall. Cylinder #5 is located on the Driver Side (First one)
firewall 4 - 8 3 - 7 2 - 6 1 - 5 front