Missing @ part/full throttle

[jinthadell]

I just developed a miss under part/full throttle. It backfires and almost sounds like I have a burble tune. I ran the car low on fuel, like 7 miles to empty. And that’s when I first noticed it. Thought I was running out of gas so I filled it up w 93, as usual. But the misfire/backfire continued. Any ideas?
It’s a 2019 GT1 with K&N intakes, Borla exhaust and a just recently removed Pedal Commander. Disconnected it last week cause it would throw on the check engine light like once a week. Right now I have zero lights on the dash showing anything wrong. Car drives fine as long as you don’t get on it. But babying the pedal and I have no issue. ‍

 

[Ohiocruiser]

Bad spark plugs? How many miles do you have on them?

 

[jinthadell]

72k. Just had my angel of a wife order the Denso 5346 1 step thru priority mail. So I guess by Wednesday evening I’ll be changing out these damn plugs

 

[Ohiocruiser]

72k is way overdue. Change them and let us know if it fixes the problem.

 

[Snicklefritz]

KIA recommends changing plugs at 42,000 miles. I think you pushed it a bit long there.

 

[jinthadell]

Yes I completely agree, 72k is too long. And they’re the OG plugs. But the miss got so bad I had to break down and buy a plug from KIA. $30 for 1 plug. I asked the guy working the service counter, “ Does it make you feel good to charge $30 for a spark plug? Not surprised you had it in stock, no one is buying them!” He must have thought I was a grumpy old f***. Right now she’s back up and power sliding properly! Lmao. Still waiting on the Denso’s to show up in the mail. $75 for the 6-pack btw. That seems like the going rate.

 

[Snicklefritz]

Replace the coil pack too, or else that cracked plug will have a sibling in a couple of weeks, give or take Check all the coil packs/boots. By 72,000 miles on old plugs, they are all probably going to need replacing.

 

[jinthadell]

Just changed out the factory plugs. All cylinders seem to be performing the same. The plugs are arranged as you would be looking at the engine from the front of the car. The extra plug on the left is the one I changed last week for cylinder number one that was cracked. It was just to get me by until my Denso’s arrived. I did the “hard” side first and wasn’t as bad as some make it out to be. And I left the intake on. 30-45 min process, not counting the dinner break. I do want to ask if maybe someone can tell me why the plug boots and plugs for cylinders 1, 3, & 5 on the pass side were dirty AF but the drivers side plug boots and plugs were clean as could be? Strange to me. No oil leaks either, just seemed like an excessive amount of dirt on them.