Code p0300 code po304

https://www.fixdapp.com/blog/p0306
https://www.fixdapp.com/blog/p0300
https://www.fixdapp.com/blog/p0304

P0300 - 303 - 304 engine misfire codes . P0340 Audi Camshaft Position Sensor https://www.autocodes.com/p0345_audi.html
Your best bet , take it to a qualified repair shop before you ruin the cataylitic converter

po301 to po304 are miss fire codes, 301 cylinder 1, 302 cylinder 2 Etc, p1399 means that this must be a Honda manufactured vehicle. All are misfire codes, Could be plugs, wires, coils. ETC, Check and you will find the problem. God-Bless!

P0300 random misfire, p0302 cylinder 2 misfire, p0304 cylinder 4 misfire, p0411 secondary air injection system incorrect flow detected, p1296 cooling system malfunction

that pertains to random secondary ignition missfire.possibbly another code to help pinpoint which cyl. is missfireing po304 #4 cyl. spark plug,boot/wire coil/or individual coil pack,ignition module.check in that order.need more info year,vin,etc.

The codes you listed starting with 3 are for cylinder miss on those cylinders. Code 300 is for a random miss.
Code 462 is for a problem with the fuel level sensor circuit.
Generally speaking, trouble codes for any vehicle built after 1996 are 3 or 4 digit. So is code 43 actually P0043 ?

PO304.Code means there is a miss fire on cylinder #4. That is what they call a generic code for all manufacters, It mostly has to do with a bad Spark Plug or Spark Plug Wire on cylinder #4. Or it could also be the coil pack going For that cylinder, Depending on the mileledge on your car. End if it is (Abuse)

this is an obd2 code trouble table, it can help you understand the meaning of code.
for p0300, you can go here.
for p0303,you can go here.
for p0304,you can go here.
for p0134, you can go here.
for p0341, you can go here.
hope help.

If you get
P0300
P0301
P0302
P0303
P0304
P0305
P0306
P0307
P0308

error codes and
you have an engine that misfires or runs rough, it can be the injector for that
cylinder or the coil pack. The P0300 code is a random misfire code and may or
may not be the above. All the other messages are for misfire of a particular
cylinder indicated by the last digit.

Test the coil pack by switching it to another spark plug and
see if the problem follows to that cylinder.

If that makes no difference, it is very likely the injector.
Disconnect the injector connector of the same cylinder and measure the
resistance. It should be 13.5 to 14.2 ohms at 70 degrees temp. It can be up to
16 ohms if the engine is hot. If you see a really high resistance or an open or
short then you can try to change the injector. If not, you can remove the fuel
rail on that side and switch the injector to another cylinder and see if the
problem follows to that cylinder.

You
need a 22mm wrench to remove the fuel pressure regulator. The other connections
are std. When all screws are removed, GENTLY wiggle the rail up and guide it
smoothly out. Don't put any sideward stress on the injector bodies.

Here is how to identify cylinders

Front of vehicle ^

1........2
3........4
5........6
7........8

All of the
injector connectors have a Black with red stripe wire. The corresponding other
wire color on the injector connector that matches with above are

red.........................white
green......................Red/black stripe
blue........................yellow
blue/red
stripe..........Red/white stripe

all trouble codes you have are miss fire codes p0304 #4 cyl p0306 #6 cyl p0300 random miss fire sounds like you may have bad spark plugs,wires,or coils