Flashing CEL and codes of misfires /2019 hyundai elantra gt n line

2019 Hyundai Elantra GT N Line :
Have been having intermittent flashing CEL ( check engine light) Loss of power/acceleration and codes: P0300, P0301 , P0302, P0304 … when Check engine light flashes I lose acceleration/power when pushing down accelerator. I can only only go 55 MPH max. All fluids are full . Using Exxon gas
No Mods .everything stock.

This started at aprox 3600 miles on Oct 2019 and continues intermittently… since last occurence on May 2020 @ approximately 33,000 miles
Currently at dealership and they are trying to diagnose… since they see 1 cylinder misfire … looks like they may replace only 1ignition coil … but when they had car back in Oct 2019 …they just moved the plugs around … until misfire went away … and did not replace any plugs or ignition coils in Oct 2019. And they said would not replace coils on the cylinders that were having misfire codes in October 2019 …/ as of this week only replacing 1 ignition coil on a different cyclinder that is currently having the misfire …

I have contacted Hyundai Customer Service … but not getting much assistance yet regarding ongoing issue.

Help … need assistance


Under warranty. You should not try to repair the car yourself or with an independent shop unless you are will to throw away your warranty. Why? Because then Hyundai will argue any problem was created by the shop.

You don’t need CarTalk, you need a lawyer that specializes in this sort of issue. Keep records of every dealer trip and every communication. Research your states lemon laws. If Hyundai can’t fix it, they may be required to buy it back.


It may come to that, but I think it is premature for the OP to be hiring an attorney.
He needs to keep at it with Hyundai customer service, and–IMHO–request an appointment with the Regional Service Supervisor.
If that fails to bring satisfaction, then it would be time for legal intervention.

In the meantime, it would definitely be a good idea to research the local Lemon Laws to see where he stands vis-a-vis that state statute.

If CEL is “flashing” do NOT drive it . Have it towed to the dealer . If it is flashing this can cause major damage and I guarantee they wont cover it even if it is under warranty . If you have it towed it is up to them to get it fixed under the bumper to bumper warranty .

This would be covered under the terms of the Powertrain Warranty, which runs for 10 years/100k miles.

The OP already told us that the car is…

You should have received a receipt for each visit for this problem. How many times have you had it in, and how many receipts do you have? Paperwork is important to prove how many visits you made. Check on line for the lemon law requirements in your state. If the dealer can’t find the problem in the prescribed time or number of visits, Hyundai must replace the car. You have to follow the rules to get that. I’m not suggesting you can petition Hyundai for replacement now, but you need to be ready just in case. You don’t need a lawyer for lemon law action.

Can you find a different dealership to go to?

Thirty thousand miles of this in 7 months could mean a problem. I don’t see why they have not replaced the spark plugs at this point instead of swapping them around. That’s a long time to be tooling around with an intermittent flashing CEL with reduced power and which is likely just exacerbating the problem.

Plugs could have been changed under warranty back then. At 33k miles not so much.

As mentioned, you need to keep records of this and copies of the repair orders stating the complaint and what if anything was done to correct it in case this becomes a Lemon Law issue.


I suspect it’s not plugs . . .

It certainly may not be plugs and at 3k and something miles should certainly not have been plugs. After near 30k miles of this problem and averaging 4k miles a month it might be now.

It’s mentioned they may replace No. 1 coil but I would think by this point the plug is also at fault either due to the coil or the plug doing the coil in. Could be coil connector, PCM, etc but moving plugs around is not something I would do.

The Dealership is giving me the run around … Hyundai customer service acts like it’s not their problem … The dealership did not fix problem …in oct 2019 … just moved plugs around until misfire went away … and now although they said they are replacing 1 ignition coil and 1 spark plug … they cant do anything for the original issue in Oct 2019 … even though it was same issue … flashing CEL … then goes off …but during the time it was flashing …and until you turn off car … no acceleration or power … dealership states they go by what hyundai states … on how to fix … alignment issues keeps going out after 1 month … .oh you must have done it …hit a pot hole or bumpy road … never have I seen car loose alignment so quickly as with Hyundais… past 3 Hyundai…add camber bolt on front … and tires wear perfect … not wearing on inside edge of tires…after 12k

Urghhh typical … dealership wants you to keep bringing it back in … and they know must people will just give up…
And taking it to 4 different dealerships just makes the process unbearable… waste consumers time and monet

How many times has it been to a dealer for this complaint? If their fix doesn’t work, take it back quickly. There is a fix that always works. It’s the lemon law. When all else fails, they must take it back and give you another car like yours that does work properly. You have to prove that the car isnt working and that the dealer can’t fix it. You do this by keeping your receipts to show that you tried numerous times to get it fixed with no full repair made.

In 1987/1988, we bought a Ford Taurus. The AC compressor stopped functioning properly and the dealer tried to repair it. They made it worse. I continued to take it back and they never could get the repair correct. On the sixth attempt, I sent Ford a letter notifying them of my intent to invoke the lemon law, and included copies of all receipts. The next time I took the car in for the same problem, the service advisor was relaxed until he looked at his screen. His eyes grew large and he was nervous. I figured that Ford told them to get it right or else. Or else would be exchanging my Taurus for another one just like mine, except that the AC worked properly. They replaced to AC compressor and didn’t have to give me another car.

You can do the same. Find out what your state’s rules are for the lemon law. When you have taken to a dealer, any dealer, more than the number of times or days off the road your state requires, sen Hyundai a letter demanding a new car. If you follow the procedures correctly, a you get your car replaced. In Maryland, it was six times. The lemon law forced them to fix my car because replacing the car was a lot more expensive than fixing it. If it worked for me, it will work for you.


Don’t necessarily fault the dealer for these persistent issues. So far, have they not charged you anything?
Have you got copies of the repair orders? A Lemon Law might be an option but that can vary by state so the total miles on the car might be an issue.

What this leads to is that warranty often pays little and sometimes nothing for issues like this. This means the mechanic(s) is working for free.

As for alignment, Hyundai is no different when it comes to alignment than anything else. You said they added a camber bolt and tires are now not wearing on the inside edges. That would definitely point to an alignment issue caused by potholes, curb strikes, corner cutting, or in the least likely scenario; a transport driver unloading it from the truck in a rough manner.