Lexus IS 2014+ :: Engine Misfiring On IS250 AWD F Sport

How this is still happening. My gf's '14 IS250 AWD has had 3 misfire code that popped up at about 8.5k, 13K, and 15k miles now. First time it happened it wasn't severe, it vibrated a bit and engine light lit up. Took it to Openroad Lexus of Richmond and they said it's a random misfire code and no other troubling codes came up. They suggested maybe it was bad gas. So they reset the ECU, cleared the code and we went on our way.

Fast forward to 13k miles, only about half a year later, it happened again, except it vibrated vigorously and the engine light is flashing. So we had it towed back this time and have them look at it again. Codes were random misfire and misfire on cylinder 3. Now this time they said the culprit is a bad ignition coil. So they replaced that and car is alright again.

At 15k miles, about 2.5 months from the last incident (a few days ago), same thing happened again. It even went into limp mode on a stretch of road that had a speed limit of 50 mph. So again we towed it in to the same dealership to have them fix it, yet again. Interestingly, the code is misfire in cylinder 5. The tech mentioned they tried swapped ignition coil and plug to see if problem will go away but it didn't so they checked the fuel injectors for fault. The injector was faulty and leaking. They saw lots of fuel in that cylinder so they replaced the injector with a new one.

She only ever gets premium for gas, so all that bad gas thing doesn't hold. And the car has always been serviced on time by Openroad Lexus of Richmond, according to their recommended intervals.