Check engine light came on. I ran the diagnostic test and...
Customer
Check engine light came on. I ran the diagnostic test and it gave me code P0304. So I changed the spark plugs and turned the check engine light off and drove it for a while. It seemed OK but then the light came back on. The strang...
Check engine light came on. I ran the diagnostic test and it gave me code P0304. So I changed the spark plugs and turned the check engine light off and drove it for a while. It seemed OK but then the light came back on. The strangest thing though, it turned back off on its own yesterday and I don't know what is going on because of that.
Mechanic's Assistant: Does the light stay on, or does it blink?
It's not on anymore at all.
Mechanic's Assistant: What year is your Spark?
The car is a 2018 Hyundai elantra
Mechanic's Assistant: Are you fixing your Spark yourself? What have you tried so far?
I just changed the plugs myself.
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Responses
Mike V.
218 days ago
Automotive Expert
Hi, my name is\*\*\*\*\*’ve been a technician on Just Answer since 2007 and I'll be helping you today. I'm sorry to hear you are having difficulties with your vehicle. I know how inconvenient car trouble is, but together, we will get your vehicle back up and running quickly.
May I ask whom I am chatting with today?
Customer
218 days ago
Kayla
Mike V.
218 days ago
Automotive Expert
HI Kayla, it's nice to meet you.
Did the engine run rough either time the light was on? did you get a chance to get the code before the light went out the second time?
Customer
218 days ago
the code was still the same the second time. The car wasn't running badly but I did notice that while it was sitting idle it would shake a lot.Like a vibrating type of shaking. I just don't get why the car would just shut the code off on its own if I didn't fix the problem the first time.I'm planning on making a long distance trip here soon so I want to be sure that the car is going to be ok.
Mike V.
218 days ago
Automotive Expert
Sorry I am not able to make a call at this time.
Ok, the same code on the same cylinder is usually going to mean the ignition coil is the problem and not the spark plug. The light went out on it's own because the problem didn't exist at the particular time the computer ran the self test. I would replace the coil on that cylinder and then see if the code returns, I suspect it won't.
Please let me know if you have more questions on this or any other thing I can do to help.
The car will be ok, but with this code I would still go ahead and change the coil.
Customer
218 days ago
Since the code went off on its own, will it pass a smog check right now??
Mike V.
218 days ago
Automotive Expert
yes, it should without a problem. It would mean the self test was done by the computer and there wasn't a problem
Mike V.
218 days ago
Automotive Expert
Phone call session started
Customer
218 days ago
Thank you so much. I really appreciate your help. Have a great day and stay safe!!
Mike V.
218 days ago
Automotive Expert
You're very welcome and thank you, \*\*\*\*\* \*\*\*\*\* you!
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Check engine light came on. I ran the diagnostic test and it gave me code P0304. So I changed the spark plugs and turned the check engine light off and drove it for a while. It seemed OK but then the light came back on. The strang...
Check engine light came on. I ran the diagnostic test and it gave me code P0304. So I changed the spark plugs and turned the check engine light off and drove it for a while. It seemed OK but then the light came back on. The strangest thing though, it turned back off on its own yesterday and I don't know what is going on because of that. Mechanic's Assistant: Does the light stay on, or does it blink? It's not on anymore at all. Mechanic's Assistant: What year is your Spark? The car is a 2018 Hyundai elantra Mechanic's Assistant: Are you fixing your Spark yourself? What have you tried so far? I just changed the plugs myself.