What is the firing order for a 2004 suzuki aerio 2 ltr 4 cylinder

Then you either have a dead hole (check compression) from an engine mechanical issue or the fuel injector is not being fired by the computer driver IC or the injector or the wiring to is defective.

http://j.gs/694045/v16-firing-order

cars have engines, and engines are option, none stated.
cars have 2 to 4 or more 02 sensors.
my guess is you have a DTC error and failed to post it, making any answer wrong (or a wild guess)
why do that?
let me now make you expert on numbers, this is all covered in the FSM.if you so choose to read it.
here it is, for $4 for 1 day. read it.
https://suzukipitstopplus.com/Products/1004-2004-aerio-service-manual.aspx

now the cheat sheet.
Bank 1 and bank 2,
bank 1 is where the #1 cylinder resides.
#1 where is number 1?, well, it's the most close to the engine
main crank pulley, or cam chain or cam drive bet end of engine.
on "V" engines it can be on either bank, side.
but on all V engines, one Cylinder is most forward, and THAT is #1
these are all standards, SAE.org , ASE, and ISO. (europe)

B1S1, would be the Bank 1, front 02 sensor. (runs AFR)
B1S2 is the rear of CAT sensor. ( only for smog)
cars come with many engine options, you never stated yours.

the scanner drops out when the power voltage drops too low.
so your 12vdc the ECU is tool low. use volt meter
to find the voltage drop point.
you mean no spark, fire is what fuel does when ignited.
and spark is first. if no spark say, i have no spark to 4 cylinders.
my guess is this.
lost DC power to ECU.
this kills spark
and loss of spark kills injection so, lost power kills injection 2 ways.
find this problem by watching spark and power to ECU.
the ECU will drop out about at 9v.
cranking the voltage usaully sags to about 11v cranking.
now you have a goal 11v min, to ECU at all times.(cept siberia)

same as all cars.
disconnect battery minus (or BOOM eat acid or fire or both,ouch.)
disconnector all alt wires, at alt.
unbolt alt. (belt off first.)
reverse above.

The ignition wire firing order for the 2001 Honda CRV 2.0 Ltr is 1-3-4-2, the cylinders in order are 4, 3, 2, 1, and the distributor fires at 1 to 3 for the back and 2 to 4 for the front. Also, everything rotates clockwise.

the firing order is 1-3-4-2

1-5-3-6-2-4 is the firing order.

right side is 1-3-5 left is 2-4-6

6 5
4 3
2 1

For the 2006 Suzuki Forenza 2.0L DOHC In-Line 4-Cylinder:

Firing Order:
1-3-4-2

Cylinders:
.........(back)........
|...4...3...2...1...|
........(front)

Let me know if this helped, or if you have additional information or questions. Feel Free to contact me at FixYa.com!

For the 3.4L V6:
Firing Order:
1-2-3-4-5-6

Cylinders:
(back of engine)
2-----------1
4-----------3
6-----------5
(front of engine)

Ignition Connections:
.........(back)
|.5..2.|.|.3..6.|.|..4..1.|
.........(front)

Let me know if this helped, or if you have additional information or questions. Feel Free to contact me at FixYa.com!