In a Ford Expedition , Ford truck , etcetera that has a gasoline powered V8 engine :
firewall
4 - 8
3 - 7
2 - 6
1 - 5
front of vehicle
Firing order is: 1-6-5-4-3-2 Cylinders are located as such: Standing at the front of the vehicle looking at the engine the bank of cylinders on the front of the engine are numbered from left to right 1-3-5 The rear bank of cylinders are numbered from left to right 2-4-6
Standing in front of the car looking at the engine Bank 1 is the rear 3 cylinders next to the firewall which are numbered from left to right 1-2-3. Bank 2 is the front 3 cylinders near the radiator which are numbered from left to right 4-5-6.
Bank 2 is the even numbered cylinders. Cylinder 1 is closest to serpentine belt and all cylinders on that side of engine are odd numbers. Bank 2 is all the even numbered cylinders and the O2 sensor is screwed into exhaust pipe somewhere between the even numbered cylinders and the cat converter.
Standing in front of the car looking at the engine, the front 3 cylinders are from left to right 4-5-6. The 3 cylinders next to the firewall numbered left to right are 1-2-3. Bank two is the bank where cylinders 4-5-6 are located. Bank one is the rear bank where cylinders 1-2-3 are located.
The firing order for the 3.1L VIN M, 3.4L VIN E, 3.4L VIN X and 3.5L VIN H engines is 1-2-3-4-5-6. The right bank cylinders are on the cowl side (rear) of the engine compartment and are numbered 1,3,5, left bank cylinders on the front side of the vehicle, are numbered 2,4,6. The firing order for the 3.8L VIN K and 3.8L VIN 1 engines is 1-6-5-4-3-2. Starting at the front of the engine, cylinders in the left bank are numbered 1,3,5 and cylinders in the right bank are numbered 2,4,6.
Back bank left to right, 1,3,5. Front bank left to right, 2,4,6.
The Sensor that is located after cat. converter on side of engine with evenly numbered cylinders.
A row of cylinders in an engine is known as a "bank" of cylinders. '
Bank 1 is the odd numbered cylinders. Cylinder 1 is closest to front of engine which is where the serpentine belt is
All GM V8 engines, except Cadillac, fire 1-8-4-3-6-5-7-2. Odd numbered cylinders are on the left, or driver's side bank. Even numbered cylinders are on the right, or passenger's side bank.
The cylinders are numbered left to right, 1-2-3 for the rear bank and 4-5-6 in the front bank. Firing order is 1-4-2-5-3-6
Firing order is 1-6-5-4-3-2 Cylinders are numbered left to right 1-3-5 on the front of a FWD engine and 2-4-6 on the rear. On a RWD vehicle they are numbered 1-3-5 on the left bank and 2-4-6 on the right bank. https://www.youtube.com/watch?v=LmYYvMg_jCs