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Hyundai Sonata GL 2003 sonata has a check engine light on,

 
Greg's Avatar
  • Answered by:Greg
  • import technician
  • Positive Feedback: 96.3 %
  • Accepted Answers: 465
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in Hyundai

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I took the car to the dealer and they did exactly what you said. Thanks!
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Thanks Greg. Will take to Service Centre to diagnose and fix malfunction....
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very good thanks for the answer i decided to get it wielded
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Thanks a lot! there was a rod that mounts on the shaft to conect to the timing...
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thanks so much man, u know u thing.
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not quite what i was after but factually correct. I think i needed to refine my...
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Simple answer, correctly identified. Thank Greg

Customer Question

2003 sonata has a check engine light on, when you turn it off wont start until it cools down, and has stalled three times in a week but starts back up once it cools down. Had a p0421 code.

 

Country: United States
Make: Hyundai
Model: Sonata GL
Year: 2003
Engine: 2.4L

Already Tried:
Before getting the code, replaced starter and battery. o2 sensors appear to be new.

Submitted: 791 days and 16 hours ago.
Category: Hyundai
Value: $18
Status: CLOSED
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Expert:  Greg replied 791 days and 11 hours ago.

Hi welcome to JA.com.I will answer your question the best I can,

Please do a good test drive for 10 mins then check for codes again.

Regards Greg

Customer replied 791 days and 8 hours ago.

Same code

Accepted Answer

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Expert:  Greg replied 791 days and 7 hours ago.

Hi .

A code P0421 may mean that one or more of the following has happened:

  • The catalytic converter is no longer functioning properly
  • An oxygen sensor is not reading (functioning) properly
  • A spark plug is fouled up.
But this code will not give you a no start problem after warm up?

Check the catalytic converter this could be blocking up and giving you this problem.

Best way to check this is when she stalls again is check and see if you are getting spark to your spark plugs.

If not then you may have the typical cam/crank sensor fault ?

When theses sensors malfunction they will not always trip a code?

Need further assistance please let me know.

Kind regards Greg

Expert Typeimport technician
Category: Hyundai
Pos. Feedback: 96.3 %
Accepts: 465
Answered: 2/11/2011

Experience: 27 year and 16 year as shop owner, import technician

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Customer replied 791 days and 6 hours ago.

How do I check to see if there is a spark to my plugs?

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Expert:  Greg replied 790 days and 22 hours ago.

You will have to pull out a coil from the cylinder head and connect a known good spark plug, then ground the spark plug on the top of the head valve cover and crank the engine over and see if the plug is sparking?

Greg

 
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