Bad catalytic converter. What are my options

[Blwhit1]

Hey guys,

So one afternoon my check engine light pops on and I went by the auto parts store and got this:

P0430 - malfunction within the catalyst system

So I am assuming that my CAT went out on my 2012 Sedan 3.8 and now needs replacing.

The next day, I was driving on the highway at about 95 MPH, and my car starts bogging out and the check engine light started flashing. Went back to have the codes read and got these:

P0300 - engine has a misfire that is not related to only one cylinder
P0430 - malfunction within the catalyst system
P0302 - cylinder 2 is misfiring
P0304 - cylinder 4 is misfiring
P0306 - cylinder 6 is misfiring

Now I am no car expert, but this cant be good. The car just hit 81k miles.

Here are my questions:

1. Would a bad CAT cause all those problems and would replacing the cat fix this?
2. Dealership said there were 2 cats on the car. How can I tell which one went out?
3. Is it an option to buy a aftermarket cat like this without affecting warranty and also able to pass emissions (The dealership wants $817 each) :
http://www.autozone.com/exhaust/catalytic-converter


Thanks

 

[homeofstone]

I think the first thing you should do is find out exactly what is wrong with the car. Guessing on problems with newer model cars just cost more money in the long run due to replacing parts not needed. Take it to a Hyundai dealer and have them diagnose what is causing the problem. You can always take it to a less expensive shop for the repair or DIY.

 

[Mark_888]

Some items on the car related to emissions may be under warranty for a longer period of time than the rest of the car. Have your dealer look at it.

 

[DubbuD]

Its a 2012, shouldn't this all be covered under the 10 yr/100k mi. powertrain warranty?

 

[Mark_888]

Its a 2012, shouldn't this all be covered under the 10 yr/100k mi. powertrain warranty?

I gave a hint above, but I guess I have spoon-feed:

The 10 yr/100k mi. powertrain warranty covers repair or replacement of powertrain components (i.e., selected engine and transmission/transaxle components) and does not include the catalytic converter. This warranty is only available to original purchasers, or CPO cars.

However, there is an 8 year - 80,000 mile Emissions Warranty required by the US Government (for all cars sold in the USA that is fully transferable to subsequent owners) that covers repair or replacement of the following original Hyundai major emissions control components, should they cause the vehicle to fail to conform to an applicable EPA-approved inspection/maintenance program:

• Catalytic Converter
• Engine Control Module
• Onboard Emissions Diagnostic Device (OBD-II)

Other EPA (Environmental Protection Agency) emissions warranty parts are covered under the 5-Year/60,000-Mile New Vehicle Limited Warranty.

https://www.hyundaiusa.com/assurance/america-best-warranty.aspx#7

 

[Blwhit1]

I think the first thing you should do is find out exactly what is wrong with the car. Guessing on problems with newer model cars just cost more money in the long run due to replacing parts not needed. Take it to a Hyundai dealer and have them diagnose what is causing the problem. You can always take it to a less expensive shop for the repair or DIY.

Thanks for the advice. Ill just have them tell me exactly what is wrong with it so I can repair it somewhere else or myself cheaper.

I gave a hint above, but I guess I have spoon-feed:

The 10 yr/100k mi. powertrain warranty covers repair or replacement of powertrain components (i.e., selected engine and transmission/transaxle components) and does not include the catalytic converter. This warranty is only available to original purchasers, or CPO cars.

However, there is an 8 year - 80,000 mile Emissions Warranty required by the US Government (for all cars sold in the USA that is fully transferable to subsequent owners) that covers repair or replacement of the following original Hyundai major emissions control components, should they cause the vehicle to fail to conform to an applicable EPA-approved inspection/maintenance program:

• Catalytic Converter
• Engine Control Module
• Onboard Emissions Diagnostic Device (OBD-II)

Other EPA (Environmental Protection Agency) emissions warranty parts are covered under the 5-Year/60,000-Mile New Vehicle Limited Warranty.

https://www.hyundaiusa.com/assurance/america-best-warranty.aspx#7

Thanks Mark, Unfortunately my car just hit 81k so that warranty is out of the question at this point. Do you think it would be a safe bet to assume that the cat that went out is on the same side as the misfiring cylinders?

 

[Mark_888]

Thanks Mark, Unfortunately my car just hit 81k so that warranty is out of the question at this point. Do you think it would be a safe bet to assume that the cat that went out is on the same side as the misfiring cylinders?

I am not knowledgeable enough on that subject to offer an opinion. Sometimes a dealer will ask Hyundai for a goodwill warranty repair if the item has a problem just after the warranty runs out. Check with the dealer and plead your case.

 

[Bill K]

You might have received the Cat code because of the misfiring cylinders. As for the misfiring, could be easy, could be bad.......Only one way to find out.

 

[Gunkk]

IIRC the only sensor for the cat is the 02 sensor. So get the 02 sensor on that side tested first. Or switch em and see if the code follows the sensor.

 

[DubbuD]

I gave a hint above, but I guess I have spoon-feed:

The 10 yr/100k mi. powertrain warranty covers repair or replacement of powertrain components (i.e., selected engine and transmission/transaxle components) and does not include the catalytic converter. This warranty is only available to original purchasers, or CPO cars.

However, there is an 8 year - 80,000 mile Emissions Warranty required by the US Government (for all cars sold in the USA that is fully transferable to subsequent owners) that covers repair or replacement of the following original Hyundai major emissions control components, should they cause the vehicle to fail to conform to an applicable EPA-approved inspection/maintenance program:

• Catalytic Converter
• Engine Control Module
• Onboard Emissions Diagnostic Device (OBD-II)

Other EPA (Environmental Protection Agency) emissions warranty parts are covered under the 5-Year/60,000-Mile New Vehicle Limited Warranty.

https://www.hyundaiusa.com/assurance/america-best-warranty.aspx#7

No need to "spoon-feed"; I'm just saying, if the car is misfiring and it was purchased new, the engine should be covered under the 10 yr/100k mi. powertrain warranty. Period. If it has a bad cat, then pull it off and put a new one on, but a misfiring motor should still be covered by Hyundai's warranty.

If it wasn't purchased new, then it may only be covered by a 5 yr/60k mi. warranty I believe it is, which means this could be simple, or it could be expensive, but the only way to know is to start digging into it.

______________________________

Help support this site so it can continue supporting you!

 

[Blwhit1]

Hello all,

Here is the update so far:

So thanks to Mark,

I am not knowledgeable enough on that subject to offer an opinion. Sometimes a dealer will ask Hyundai for a goodwill warranty repair if the item has a problem just after the warranty runs out. Check with the dealer and plead your case.

I called Hyundai and since it was 500 miles past warranty, they provided a free cat but I had to pay the install of $380. I dropped off the car and picked it up the next day and drove away with it still misfiring. The service adviser told me to replace the spark plugs because that is probably the cause of the misfiring. So I dropped $150 more on NGK spark plugs and got all that changed. While changing, I noticed water in my oil which must be new since I had them provide a oil change less then 2 weeks ago. Even after replacing the spark plugs, 3 of the cylinders are still misfiring. After dropping the car back off, they said they have not figured out what the issue is but it could be bad injectors. They also said I am up to 4 cylinders now that are misfiring.

When I get some more info from the dealership this afternoon, I'll post an update

 

[Mark_888]

While changing, I noticed water in my oil which must be new since I had them provide a oil change less then 2 weeks ago.

Any chance that the water is from the coolant system (half water, and half coolant)? If so, that probably means there is a bad gasket, or a crack in the block.

 

[homeofstone]

Water in oil is very bad. Has the car ever overheated? Have a pressure test done on the cooling system. If it does not hold pressure and /or pushes water into cylinder then a head gasket is bad or head is cracked.

 

[Blwhit1]

Water in oil is very bad. Has the car ever overheated? Have a pressure test done on the cooling system. If it does not hold pressure and /or pushes water into cylinder then a head gasket is bad or head is cracked.

I agree! Hopefully they can figure out where the problem spot is. All I can say is I am not driving that car until they fix it 100%.

 

[PMCErnie]

It's simple enough. The Cat isn't part of the engine, or the transmission.

 

[DubbuD]

But the problem clearly isn't the cat. It's quite obviously an issue with the motor. Unless a cat is plugged solid, I don't think a motor is going to misfire because of it; or at the very least is is highly, highly unlikely. And if a 2011 is plugged solid, that signals a greater issue than the cat itself. Further more, Its now misfiring on 4 cylinders, assuming that 1 of those is not exhausted through the bad cat, and there's water in the oil. It's a bad motor; or a bad part on the motor, likely the head or head gasket if there's water in the oil, and should be backed by Hyundai's 10 yr/100k mi. powertrain warranty if the vehicle was bought new in 2011.

 

[PMCErnie]

Yes, you are now comprehending. A cat failure would not be covered under the 10/100,000 powertrain warranty.

 

[DubbuD]

But, it isn't, and hasn't been, a cat problem......................
Why are we still stuck on the cat? The motor, which is clearly broken and not running properly, should be covered under warranty. That's all I'm saying. Not the cat, the motor.

The thread is kinda inappropriately named tbh. Should be named "Engine Misfiring, Possible Bad Cat"

The bad catalyst code could be thrown for a number of reasons, since its just a sensor that is sensing the amount of emissions coming through the system. The code is literally just thrown whenever it senses something is wrong and the catalyst is not operating at what it perceives as optimal performance. Its the misfire codes which are most alarming, since those are actual, mechanical issues, and seem to be getting worse, not better. It is also likely that a leaking head, or the misfires caused the code to begin with, and then the other codes to show the problems were thrown after the general catalyst code. Since there does appear to be water in fresh oil, that to me screams bad head or head gasket, which could lead to a P0430 Code, and also lead to misfires.

Its a motor problem, it should be covered. It is NOT a catalytic converter problem causing all of these symptoms.

 

[PMCErnie]

DubbuD, read your post #4 in this thread. You were wrong then. 'Fess up. The point was that IF it had been the cat, it would not have been covered by the 10/100,000 powertrain warranty.

 

[Gunkk]

The "misfire" reports were almost certainly from o2 sensor readings. Water in the oil = blown gasket (most likely) or crack in a head or block (less likely).

Amazes me how dealers will blindly do work as long as they get paid, instead of looking and thinking and figuring it out first.