Spark plug NGK or AC DELCO

Next day guy at the auto parts store tells me to try ngk iridium’s and it works automatically. If you’re planning to replace your spark plugs save your self the time and money and buy ngks over anything.

I replaced the plugs again (from Brisk to NGK R7437-9) and rotated the coil packs to try and resolve the misfire issue. I also re-flashed both the ECU and TCU tunes, and the cold start misfire issue appears to be fixed.

AC Delco double platinum spark plugs belong in that engine.

Atualmente uso velas e bobina NGK. Perfeitas.

I’ve been a Toyota certified master diagnostic tech for nearly 30 years. I can tell you that I’ve seen Toyotas come in running poorly and all we do is scrap the off brand plugs with either NGK or Nippondenso and the car runs fine again.

Based on your parts list, I'd recommend getting the Denso or Hyundai branded ignition coil. Denso is the OEM for Hyundai. For spark plug, get the NGK 9723. These are the OE spark plug for Hyundai.

I've had misfiring when I installed it dry and torqued to spec on my Civic 8 gen. No misfiring after anti seize...

Just changed the plugs on mine @ 75k 2 weeks ago. DIY EASY! Installed the NGK Laser Iridium ILKAR7L11 94124 plugs. Old ones screwed right out.

Here’s a link that may be of help. Your plugs are quite fouled and even at end of life plugs should not look like that.

Well, shit. I just put new plugs in two months ago following what EQT recommended then! I didn’t know of these failures with projected tipped plugs. Guess I should have spent a little more and bought non projected at the time, dammit.