P0304 Code: Cylinder 4 Misfire - Causes and Troubleshooting Guide

so today I talk about a P0 304 code what it is and how you go about fixing it and so what is a P0304 code well it's a cylinder 4 misfire detected and what does this mean well basically each cylinder inside of the engine needs to have the correct air fuel ratio mixture going into it and then at the right time the spark plug's going to send out a spark that ignites this mixture which is going to cause a small explosion which is going to send the Piston down which is going to turn the crank and this is to keep the engine running but when you get a misfire code something's gone wrong with this for some reason this small explosion is not happening or it's happening sometimes but not other times and so it's going to have to be troubleshoo to know why and a P0304 coat is going to point to the number four cylinder on the engine so if you go look up your engine cylinder locations and you find a diagram on it cylinder number four is going to be the one causing the issue and it's going to be the one to go and take a look at and one thing to note about misfire codes is that if you're only getting a misfire on one cylinder then you really only need to go check the components on that cylinder so this would be like the coil on that cylinder the fuel injector on that cylinder or things like this but if you're getting multiple misfire codes then that can point to something else so for example if you had like a p03000 code and you were also getting like a p031 p0302 along with this P0304 code that would point to something that would affect the whole engine and so that'd be something like a weak fuel pump a Clogg fuel filter a coil pack something along these lines but if you're only getting this p 0 304 code then you only need to go check the components on cylinder number four and so what would be some possible causes of a p 0 304 code well it could be a bad spark plug that spark plug might have fouled out could be the spark plug wire going to the spark plug it could be a bad coil on cylinder nor 4 it could be a bad fuel injector if you have an older engine that has a distributor cap it could be a bad distributor capab and it's also possible that that cylinder is having some kind of issue like it's got a bad valve or it's leaking for some reason like a bad head gasket although that's not too common it is possible that there's some kind of mechanical problem on cylinder number four and so how would you go about troubleshooting a p 0 304 code well the main thing you're going to want to go check on that cylinder is you're going to want to make sure that it's getting sparked from the coil and you're getting gas so first thing to do is go locate cylinder number four on your particular vehicle so you know which cylinder is having the problem the next thing to do is to check out any spark plug wires and the coil going to that cylinder there is different types of coils that can be on the engine but they basically all do the same thing they're just sending spark to that cylinder to ignite that air fuel ratio mixture at the correct time and so the next thing to do is be sure that that coil is working and it is sending spark to cylinder number four and there's a few different ways you go about doing this if you have coils like this on each cylinder you could swap it with a good one like cylinder number three and just see if the problem follows so for example if you swap this out with cylinder number three and then you got a p 0303 code then you would know it's a bad coil and you can replace it another way to go about checking the coil is to check to see if you're getting spark on cylinder number four and one way to do this is to use the inline spark tester tool these are real low cost tools usually less than like $10 $15 I'll put a link Down Below in the description if you need one but basically one side goes on the spark plug and the other side goes through the coil and then you start up the engine and if there's a spark you'll be able to see it inside of here you'll see the spark jumping inside of here but if there is no spark then you won't see it inside of here there won't be nothing happening and so this is a real easy way just to check to see if you're getting spark and if you are getting sparked then this means that the coil is working and you can move on to checking other things but one of the first things to do is to check to be sure that that coil is working and that you are getting spark to cylinder number four if you are getting spark on cylinder number four then the next thing to do is go check out the fuel injector and the fuel injector wiring and basically be sure that it's working again there's a few different ways you go about doing this if they're easy to get to you could swap it out with another cylinder and see if the problem follows you can also test these with the multimeter and things like this and be sure that it's working there's some good YouTube videos on how you go about testing the fuel injector and also check the wiring going to the fuel injector on cylinder number four because keep in mind anything wrong with the wiring open short bad connection is going to cause the same symptoms as a bad component so be sure to keep that in mind but the next thing to go and check is be sure that that fuel injector on cylinder number four is working and so that's basically it I just want to give a basic overview of how you go about fixing a vehicle with the P0 304 code if you have anything to add please comment down below if you have any questions ask me I'll try to answer them this video happen please click like please click subscribe and have a good day