Catalytic Converter - replace all 4?

[dashambley]

I don't do a lot of work on my car so if someone else has a different suggestion/direction on what my potential solution is, I'm all ears!

I have a 2011 Genesis 4.6L Sedan and I’m trying to get other user’s experience on using a Catalytic cleaner such as CataClean long-term prior to having to replace the Catalytic Converters in their current condition. I’m currently at 110k miles. My only other engine/exhaust problem that I ever had was an Evaporative Purge Flow (PO496 - promptly replaced at 99k miles). At 106k miles my Check Engine light came on with P0430, bank 2. I put a can of Cataclean in the tank and it ran fine until a few weeks back. I took it to the shop and I now have PO420 and PO430 codes, and the shop says I need to replace all 4 Cat Converters, get an engine tune-up, and fuel induction service. The 4 installed converters will cost $7k. At a bare minimum I would also need to invest $1k to resolve the starting issue and probable cause of the cats going bad. What I don’t have is a GUESTIMATE of how long the existing cats would last if the plugs were changed/fuel injectors cleaned and I used CataClean for any other issues.

Any experience that users can share on the short- or long-term use of catalytic cleaners would be appreciated.

 

[NSXNEXT]

You should only ever have to replace two of the catalytic converters. Only two of them have O2 sensors connected to them so you could literally remove the secondary cats and you'd never throw a code.

 

[dashambley]

You should only ever have to replace two of the catalytic converters. Only two of them have O2 sensors connected to them so you could literally remove the secondary cats and you'd never throw a code.

Thanks for the feedback. Given the front two are the most expensive (~$5k installed), I'm assuming those are the two to focus on.

A broader question - if the two identified problem areas are fixed (i.e., plugs are replaced and fuel injectors are serviced) and another can of a catalytic converter cleaner is used to clean the catalytic converter, is it reasonable to believe that the problem will be resolved, if only for another 10-20k miles?

I know I don't want to spend $8-9k on a 12 year old car to permanently fix the problem (or even spend $6-7k when only replacing the front converters). However, a $1k repair that gives me another 10-20k miles on the 12 year old car is worth further consideration.

Any additional suggestions

 

[NSXNEXT]

Thanks for the feedback. Given the front two are the most expensive (~$5k installed), I'm assuming those are the two to focus on.

A broader question - if the two identified problem areas are fixed (i.e., plugs are replaced and fuel injectors are serviced) and another can of a catalytic converter cleaner is used to clean the catalytic converter, is it reasonable to believe that the problem will be resolved, if only for another 10-20k miles?

I know I don't want to spend $8-9k on a 12 year old car to permanently fix the problem (or even spend $6-7k when only replacing the front converters). However, a $1k repair that gives me another 10-20k miles on the 12 year old car is worth further consideration.

Any additional suggestions

Not a clue. It's a roll of the dice.

 

[dashambley]

Unfortunately that was what I was thinking as well. I haven't seen smoke or any other unusual signs on the exhaust, and up until a week or so, I didn't have any issues to speak of.

I'm thinking I will invest in a tune up, fuel injection cleaner, and a can of Cataclean. If it works out to the point that it can be a reliable around town' car, great. If not, I will reevaluate then.

Thanks for your help!

 

[JEBIV]

A car needing a tune up ( plugs) could certainly set both codes. I would try the plugs first for sure !

 

[mikec]

The OBD-II monitoring system uses an heated oxygen sensor (aka "HO2S" in Hyundai manuals and simply "O2 sensor" on the Internet) upstream of each primary cat converter to monitor engine air:fuel ratios and a second sensor downstream of the cat converter to monitor the cat converter efficiency. A dying O2 sensor, or one that has been contaminated, downstream of the cat may cause the OBD-II system to complain the cat converter is dying. Exhaust pipe leaks will screw up the readings too. The upstream sensor output voltage wiggles between two values as the computer fine-tunes the air:fuel ratios above and below the optimal stochiometric point; the downstream sensor outputs a fairly constant value. As long as that value is above a certain voltage the OBD-II system is happy. Aging or damaged sensors respond more slowly and with lower voltages... Oxygen sensor output voltage are very low power: any extra electrical load will "pull down" the output voltage too. Bad/dirty connections at the sensor, at the computer, and damaged wiring insulation will cause problems.

Misfires, oil leaks, and leaking fuel injectors create raw gas or oil into the exhaust which quickly trashes cat converters. Getting the converters very hot - a long uphill drive for example - can help burn off some crud. I have zero experience with cat cleaner products... and wonder if any crud cleaned from the converters ends up in the downstream oxygen sensor or if the cleaner itself can damage the sensor.

mike c.

 

[amartz]

I had my 2012 3.8 trying to tell me my cats were bad. Turns out it was the O2 sensors that were bad. Replacing those is a lot cheaper than replacing cats.

 

[Andyj]

My 2015 3.8 sedan with 73K miles is throwing a P0420 code and I tried a cataclean treatment and the code cleared but came back in a few days. Trying to diagnose the O2 sensors.

 

[Charlie1982]

Might be worth running another bottle of CataClean through the system, too. (In case your cats got partially cleaned, and need the job finished) I don’t know for sure, though…

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[G-571230]

I had my 2012 3.8 trying to tell me my cats were bad. Turns out it was the O2 sensors that were bad. Replacing those is a lot cheaper than replacing cats.

My 2015 3.8 sedan with 73K miles is throwing a P0420 code and I tried a cataclean treatment and the code cleared but came back in a few days. Trying to diagnose the O2 sensors.

Hey, did you ever find out what the problem is with your 3.8 I have the same Codes trying to determine should I change the cat or did it end up being it tune up or something like that?

 

[Andyj]

I tried the DuraLube extreme cat cleaner and it cleared the P0420 code, but the code came back in about a month. Going to replace the Bank 1 downstream O2 sensor next.

 

[Green One]

I tried the DuraLube extreme cat cleaner and it cleared the P0420 code, but the code came back in about a month. Going to replace the Bank 1 downstream O2 sensor next.

My experience has been to do both of them..

 

[Andyj]

My experience has been to do both of them..

So replace both downstream and upstream Bank 1 O2 sensors?

 

[G-584926]

If you are doing pre cats, do them both..If you chose the post cats, do them both..