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George H.
George H., ASE Certified Technician
Category: Car
Satisfied Customers: 18770
Experience:  ASE Master Tech 15+ yrs, AAS Automotive Technology, Factory trained Asian specialist
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2004 Hyundai XG350: light came..I needed a catalytic converter..tune

Customer Question

I have a 2004 Hyundai XG350, which I have been very deligent about having maintenance work done. Recently my "check motor" light came on and was told at the dealer's service dept that I needed a catalytic converter. They then told me that once I get that replaced I should get a tune-up so as not to have it happen again. Everything and everyone has said that this part should last the life of the car. Am I being ripped off due to being a female? What would be my recourse? My car has 81,500 miles on it. I planned on keeping this car for a few more years. HELP!!
Submitted: 7 years ago.
Category: Car
Expert:  George H. replied 7 years ago.

Hello I will help you with your question,


If the vehicle is showing a P0420 code you will have to replace the catalytic converter. You are at the point that a lot of maintainence is due, the sparkplugs need to be changed (they are right that failed plugs can cause the cat to fail) the fluids need to be changed and the timing belt should have been changed along with the drive belts at 60,000 miles. If your battery has not been changed it is due and the brakes are close to worn out if they have n ot been replaced.

I hate to hit you with this all at one time but the reason that Hyundai only has a 60,000/5year bumper to bumper is that they know when these things wear out. If you have replaced or have done the services certainly they don't need to be done but if they have not been done tet it is time.



The catalytic converter is covered by the federal emissions warranty for 8years/80,000 miles so you are out of warranty on that coverage. If you need to do all or most of this service I would talk to the sales department about trading the vehicle as it may make sense rather than sinking a bunch of money into this car. You would have to decide that.


Please let me know what questions you may have about this


Thank you



Customer: replied 7 years ago.

So, you are saying that this is normal for a car w/ 80,000 miles? Once the car gets a tune-up and this converter replaced, should I be ok for a while?

My friend says that a product called Seafoam would have helped deter this problem. True?

Expert:  George H. replied 7 years ago.

Your friend is almost correct, the mandated warranty is 8/80 so the manufacturers make the converters to last about that long. Some last much longer and some fail sooner. The MFG is playing the odds to keep costs as low as possible. If there is a misfire in the engine which can be poor fuel delivery or poor spark the unburned fuel goes to the cat and is burned there. This excess heat can damage the cat. If additives or coolant get to the cat they can coat the honeycomb that the exhaust passes through and this will cause the cat to fail as well.


This is why you are being urged to get a tuneup as any misfire can damage the cat in a very short time so you want to keep the engine running as well as it can at all times.


If you get the tuneup, have had the belts changed, had the brakes and battery done then replacing the cat should allow you several more years of normal operation of your vehicle


Let me know what I can do to help you with this


Thank you



Customer: replied 7 years ago.

One more question...........

So, does the Seafoam product help avoid issues like I'm having or is it a waste of money?

Expert:  George H. replied 7 years ago.

Regular maintainence and using top tier gasoline will do more than Seafoam will to preserve the function of the catalytst. The Seafoam may help with drivability by cleaning the injectors and if used in the oil keeping the rings from sticking but is is very old technology so I would save your money



Customer: replied 7 years ago.

OK, I more question! (-:

When you say top tier........

I only buy B&P (Amoco) or Sunoco. The dealership told me that my car will run on regular and to burn that. My Father always told me I should burn higher than regular. Your opinion?


Expert:  George H. replied 7 years ago.

You should use what the engineers that designed the engine chose, in your case, regular.


Here is a link to the top teir website for further information about this


Please let me know if you have further questions


Thank you





George H. and other Car Specialists are ready to help you
Customer: replied 7 years ago.
Thank you for your feedback.
Expert:  George H. replied 7 years ago.

Glad to help and thank you for using JA!!