P0300 comes back

[Bryan97]

Hey guys have a 2019 Ram 1500 5.7 hemi tradesman etorque. I had replaced 2 coils and all 16 spark plugs it went away for a while and then all sudden it started again for cylinder 5 "P0305" when I pulled coil an spark plugs on that it wasnt bad but I had a vaccum leak from the breather tub to the oil fill cap I put hose clamp and it cut it out when I deleted the codes but what I wastold I was running to cheap of gas. i had a P0300 come back and I put octane booster in my tank and ran it and it did fine and didnt have issues or anything and the P0305 never came back but when I went to fill up my gas tank with 93 gas it started random missfire "P0300" again but I put octane booster it started to run fine and I deleted the code again so I can pin point it more. Any info what could keep this coming back let me know please. I also checked spark plugs on the passenger side and they all looked good but imma check the driver side tomorrow after work. But any ideas an what could cause this would help big time. Thanks

 

[stevj]

Swap the injector for whichever cylinder is misfiring with any other cylinder to see if the misfire follows. If you have random misfires in all cylinders, run some Techron in a tank or two of gas and see if that helps: you could have dirty injectors. Also, if you're not already, use Top Tier gas exclusively.
Top Tier gas has the proper mix of additives to help keep fuel system clean. Top Tier gas is at: Costco, Exxon/Mobil, Shell, Chevron and a few others.

Steve

 

[Brutal_HO]

Not a hemi, and I don't run top tier gas (which has Techron in it) but I religiously run a bottle of Techron every 5K miles through our gas cars - Audi and Subaru both 100K+ and a new Kia, and never have any fuel related issues.