[Rob Gannon]

I've have a 2019 Elantra N-Line I bought new. A few months ago the check engine light came on. I contacted the dealer and scheduled an appointment. In the interim I had a parts store run a diagnostic which came up as all four cylinders misfiring.

The light turned off but I still went to the dealer who found no problems. It came on again and this time ran really rough. The dealer cleaned the valves and it was good again. The light came on again and at the advice of their headquarters the dealer changed the valves. Its on again.

Has anyone else had this problem? I'm curious if it could be something to do with the higher amount of ethanol in the fuel lately.

 

[Rob Gannon]

FOLLOW UP - The light came on again. I needed to refuel and I chose a different service station. The light turned off and has stayed off since then.

 

[zooid]

Mine (2020 EGT N-line) was going into limp mode frequently whenever I accelerated. Not what I bought the car for.

I changed out the coil packs with MSD coilovers from Summitt Racing ($125 apiece = $500), specific to the car. Fixed it right up for the most part.

About monthly, I'll punch it and it'll go limp. Pull over to the side of the road, turn off the car, open the door to discharge electrics and clear DTC/CEL, restart the car and away she goes like nothing ever happened.

Gas may have something to do with it; but, I believe there's some substandard OEM parts in the ignition system.

-zed

 

[Deathjam4]

did they even check or replace the spark plugs and coils ? or even check the injectors? these are the two most common symptoms of miss fire in these cars lol i am hugely surprised they bothered doing that heavy of work when the solution is often to replace those two things hehe

 

[Midenginedriver]

FOLLOW UP - The light came on again. I needed to refuel and I chose a different service station. The light turned off and has stayed off since then.

What brand was the gas station? Major brand? I also have an GT N Line

 

[Midenginedriver]

FOLLOW UP - The light came on again. I needed to refuel and I chose a different service station. The light turned off and has stayed off since then.

I have found as suggested on this forum to run gumout regane fuel cleaner and I no longer have the check engine light

 

[zooid]

My 2020 EGT N-Line now runs like an I30 N. No kidding, borderline scary fast.

My solutions:

1. Swap out coilovers. They're a Hyundai-mandated recall for just about every GDI 1.6 Turbo in their lineup. Long story short, they're utter trash. Problem is, the company-based replacements are scarcely better. Get the coilovers I listed above and the majority of your problems with misfires will go away. Roughly $500 shipped.
2. Get Gumout Fuel System Cleaner with Regane (GDI-safe, won't void warranty) and use it every 3K miles or so. I suspect the GDI gunks up the cylinder heads. This fixes that issue. None of the other treatments I've found at twice the price or more -- during a Gumout lack of stock, specifically -- seem to do anything to improve performance and gas mileage.

If you want your car to go really fast (like I demand of my automobiles):

1. Get a plug-in removable turbo tuner from TDI, out of Chelmsford, UK. Five minute install/removal for shop days. No record in ECM, warranty-safe. Roughly $350 shipped.
2. Get Pedal Commander for instantaneous throttle body response. NOTE: Similar items are available at various price ranges; but, I can only comment on the qualities of what I have on the car. Small device, Bluetooth-enabled. I have mine secreted away below the dash and use BT to turn it on/off and to select modes. I just turn it off for shop days; no logs, warranty-safe. Roughly $250 shipped.

In closing, ya gotta get the Hyundai coilovers out of your car. I'm sorry, cuz $500 is a big bite. But, doing the other things without addressing the root cause of misfires is like building a mansion on a garbage dump. Still, for a total of ~ $1,000 you can get a vehicle with in excess of 246 hp and 250 ft. lbs of torque and instantaneous acceleration to all that power. My car 0-60 sub 5 seconds, just letting the DCT handle shifting (non-sport mode) and half-pedal on the throttle. The only time I have to use the flappy paddles is to shift 3 times in 1 second intervals to 7th gear after the pull; never gets above 6K RPM. I've got great tires and they frequently break away on a hard pull, even when already rolling... My car is now the best traffic-beater I've ever owned! And 32.8 MPG, driving like an utter maniac. YMMV.

My settings:

1. TDI Tuner: level 4 (default) out of 7
2. Pedal Commander: Sport, bumped up 2 notches.

Happy Motoring,
-zed

P.S.
DCT shifts fantastic, now; no more hesitations or 'uncertainty' as it auto-shifts.

 

[cyberkeenan]

edit

 

[cyberkeenan]

My 2020 EGT N-Line now runs like an I30 N. No kidding, borderline scary fast.

My solutions:

1. Swap out coilovers. They're a Hyundai-mandated recall for just about every GDI 1.6 Turbo in their lineup. Long story short, they're utter trash. Problem is, the company-based replacements are scarcely better. Get the coilovers I listed above and the majority of your problems with misfires will go away. Roughly $500 shipped.
2. Get Gumout Fuel System Cleaner with Regane (GDI-safe, won't void warranty) and use it every 3K miles or so. I suspect the GDI gunks up the cylinder heads. This fixes that issue. None of the other treatments I've found at twice the price or more -- during a Gumout lack of stock, specifically -- seem to do anything to improve performance and gas mileage.

If you want your car to go really fast (like I demand of my automobiles):

1. Get a plug-in removable turbo tuner from TDI, out of Chelmsford, UK. Five minute install/removal for shop days. No record in ECM, warranty-safe. Roughly $350 shipped.
2. Get Pedal Commander for instantaneous throttle body response. NOTE: Similar items are available at various price ranges; but, I can only comment on the qualities of what I have on the car. Small device, Bluetooth-enabled. I have mine secreted away below the dash and use BT to turn it on/off and to select modes. I just turn it off for shop days; no logs, warranty-safe. Roughly $250 shipped.

In closing, ya gotta get the Hyundai coilovers out of your car. I'm sorry, cuz $500 is a big bite. But, doing the other things without addressing the root cause of misfires is like building a mansion on a garbage dump. Still, for a total of ~ $1,000 you can get a vehicle with in excess of 246 hp and 250 ft. lbs of torque and instantaneous acceleration to all that power. My car 0-60 sub 5 seconds, just letting the DCT handle shifting (non-sport mode) and half-pedal on the throttle. The only time I have to use the flappy paddles is to shift 3 times in 1 second intervals to 7th gear after the pull; never gets above 6K RPM. I've got great tires and they frequently break away on a hard pull, even when already rolling... My car is now the best traffic-beater I've ever owned! And 32.8 MPG, driving like an utter maniac. YMMV.

My settings:

1. TDI Tuner: level 4 (default) out of 7
2. Pedal Commander: Sport, bumped up 2 notches.

Happy Motoring,
-zed

P.S.
DCT shifts fantastic, now; no more hesitations or 'uncertainty' as it auto-shifts.

When you talk about the coil packs and then the coilovers, are you talking about your ignition and then your suspension?
What did you replace the coil packs with?
Side question, what tires are you running? Stock wheels?

 

[zooid]

When you talk about the coil packs and then the coilovers, are you talking about your ignition and then your suspension?
What did you replace the coil packs with?
Side question, what tires are you running? Stock wheels?

The car is completely stock with the exception of "coilover"="coil packs" and plug-ins noted above. No tunes on the ECM for maintenance to find, nor other mechanical add-ons. Great, stiff frame; no LSD, but multi-point suspension requires no upgrades. I replaced the OEM coil packs with MSDs bought at Summit. Here's a link, now only $166.95 for a set of four, but only 6 sets left. Hurry, if you're interested.

https://www.summitracing.com/parts/msd-826943/make/hyundai/model/elantra-gt/year/2020

And finally, yes, stock rims; but replaced OEM tires inside of a year (about 30K miles, for me, due to excessive and uneven tread wear around 18K miles) with Continental ExtermeContact DWS 06 Plus from TireRack.com. Lighter tires and low rolling resistance for better MPG. DWS stands for 'Dry', 'Wet', 'Snow'. As they wear, the 'S' marked in the tread disappears, then the 'W', but they're still good in dry conditions for another period. I have sworn by these particular Continentals for over 15 years, put over 70,000 miles on a set and still had W and D left! Superior traction, year-round. Great in snow, manageable in ice, superb in everything else. And like I said, my driving style is beyond 'aggressive'.

If you don't drive far daily, I guess the stock tires are okay (sorta)...

Hope this helps.
-zed

P.S.
If you 'ungranny' the car, she's a real goer.

 

[cyberkeenan]

Awesome, thank you for the explanation, well stated.
My biggest complaint is the stupidly slow off the line at low speed. So I think the pedal fix will be a win, and I am leaning towards these coil packs

https://www.summitracing.com/parts/msd-82694?rrec=true

 

[zooid]

Awesome, thank you for the explanation, well stated.
My biggest complaint is the stupidly slow off the line at low speed. So I think the pedal fix will be a win, and I am leaning towards these coil packs

https://www.summitracing.com/parts/msd-82694?rrec=true

That's the correct coil pack set.

The pedal-by-wire 'electronic lag' delete and turbo tuner (the only one I'd trust is the TDI, since there's a metric sh!7 ton of snake oil out there in this category) really go hand-in-hand. I've tried both separately and -- while obvious gains were noted in both instances -- when you use them together the results are nothing short of awe-inspiring!

I'm gobsmacked and grinning, launching from a red light, 90 degree left turn onto an on ramp of a 65mph 4-lane in roughly half the time it took you to read this.

About 6 seconds 0-70 mph, including the twin 40-degree twists on the ramp that require acceleration pull offs at each apex. The combination of Pedal Commander and TDI keeps the revs up and 3rd gear -- which neither of them will do separately -- during the pull off and once acceleration is resumed, you pick up right back where you left off in the power bands (DCT, Normal mode, no flappy paddle gear changes).

At half pedal and under 6K RPM throughout... Holy Insert Expletive Here!

-zed
“The whole is greater than the sum of the parts." -Aristotle, "Metaphysics"