Cylinder 2 and 5 misfires!

[Never thought]

Hi all,

My Stinger GT is lightly modified with a Stillen air intake and SSR secondary cat deletes. I have never been tuned nor have I ever used any of the tuning boxes. The CEL came on, car was driving fine, but I took it to the dealer to get checked out. They said it was a historical code for a cylinder 2 and 5 misfire. They inspected the coils and plugs and everything was intact. They couldn’t find any issue with the car. I’ve also only used top tier 91 octane gas (93 isn’t available in AZ).

Any thoughts on what may have caused this or could have been as simple as a hiccup?

 

[eflyguy]

I'd wait and see if it occurs again, and use my own code reader to see if there's a number of them, or just a single instance.

Really hard to say without knowing that info. If it had been a string of them, I'd be inclined to think there's an ECU issue. Certainly, your mods are not causing it.

 

[StungBlueGT2]

Hi all,

My Stinger GT is lightly modified with a Stillen air intake and SSR secondary cat deletes. I have never been tuned nor have I ever used any of the tuning boxes. The CEL came on, car was driving fine, but I took it to the dealer to get checked out. They said it was a historical code for a cylinder 2 and 5 misfire. They inspected the coils and plugs and everything was intact. They couldn’t find any issue with the car. I’ve also only used top tier 91 octane gas (93 isn’t available in AZ).

Any thoughts on what may have caused this or could have been as simple as a hiccup?

I had the same issues with my stock NGK plugs and that was before I had intakes and exhaust. It was due to the improperly gapped OEM plugs(some as bad as 0.036”) and Kia service didn’t even know to measure them to make sure they were uniform and up to specs. They checked and said everything looked fine, but my issue didn’t go away. After much research and realizing others had similar issues I went back to Kia and explained the situation other Stinger owners were having. I luckily had a cool service manager and he offered to change my plugs at no charge. I requested to have my own better & pregapped plugs installed and he agreed. After that my issues went away and I’ve had better overall performance with the properly gapped plugs. If the problem persists see if they will test the gaps for you, or swap them out with better and/or uniform gapped plugs.