engine misfires

Generally you replace spark plug wires and spark plugs, one at a time, so you don't get anything in the wrong place. Note the picture, the spark plug wire routing. You can check for applicable trouble codes. One way to check codes, is to use obd2 code reader that will work with your vehicle.
There is vehicle repair guides, at top of page, click on the link, a lot of good information.

Hello HERMAN CRUZ,

Here is a link that features an article with written step by step instructions and pictures explaining how to do the scan yourself. Also, I have included a link to our YouTube channel with a how to video on code scanning.

This is applicable even if your check engine light is not on.

Most scanners are inexpensive to purchase, you can purchase one online from sites like Amazon.com

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

https://youtu.be/YV3TRZwer8k

Once you have the code number(s) please get back to us so that we can further assist you. We are always happy to help.

Thank you for visiting 2CarPros.com.

Kindest regards,

Renee
Admin

I’m having misfires on 4 and 6 at the front. I checked both cable and spark plugs and they look good. Codes are p0304 and p0306. I am not sure if it might be the coils.

Hello my name is Dave.

The problem is highly unlikely to be the coil pack because the system on your car is what is referred to as a "waste spark system" meaning two plugs fire at the same time off the same coil, so even though you have six cylinders you only have three coils in the coil pack and four and six don't share a coil therefore it would be almost impossible for that to be the cause. If you have checked that you have the firing order correct and that you plugs are gaped correctly and you still have a misfire the next thing I would do is to change the plug wire positions to make sure that they aren't faulty or damaged (I realize they are new but it's easy insurance) then clear the codes and run or drive the car until the MIL comes back on, check the codes and see if the misfires changed position. If the misfire changes cylinder number there is an issue with your wires, if it doesn't the next thing I would do is change the injector positions in the same manner, personally I would start by taking just one of the injectors from a misfiring cylinder with one that isn't and again clear the codes and run/drive it until the code returns. If the misfire follows the injector then that is your issue, if it doesn't it is likely a mechanical issue with your engine. If you can run these diagnostic tests and need further assistance just let us know the results we will be happy to guide to further. Again thank you for using 2CarPros.

I fixed the two misfires I guess you can say (I re-gaped them a bit and checked the wires to make sure they functioned) but as I sort of was suspicious of it is an evap leak (P0171) or well system to lean but same thing. So I’m going to smoke out the engine and try to pin point the leak and fix that. then hopefully there will be no more misfires and bad fuel economy.

Also, with the swapping the spark plugs from one cylinder to another I did that and I couldn’t tell off the bat because it had taken a second for the engine light to come on, but I did it regardless and it’s a helpful tip to see whether it’s a faulty spark plug or gaped incorrectly or even a bad wire for anybody who might come across this post in the future.

Good find on that, for the evap problem please post your new question here, you must be logged in.

https://www.2carpros.com/questions/new

Cheers, Ken