Check engine light came on.. Catalytic converter

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Hi everybody. First time QX owner here. Just bought it this weekend and drove 44 kms and got the dreaded 0420 code. Im sure one of the cats are probably screwed but my questions is this. Has anybody just gutted the cats and put in a 02 simulator? I have done this on other vehicles before and it works great. Just wondering if this is an option on this engine and if anybody has had success doing it?

Thanks everyone.

An O2 simulator? They make them... but there could be fines for circumventing the state / federal emissions laws if you get caught.

Also an update..... no CEL light. Just completely vanished.... Wife now has 104k miles on it. The timing issue was resolved months ago (when the notices first came out), and it wasn't until after that (around 90k) that the CEL came on. As I said before.... I cleared the codes with Nissan Consult III, and the CEL light came back on a day later.... did nothing else, and then.... "POOF" CEL light gone, no more errors, and hasn't come back since....

Still mystified...
 
An O2 simulator? They make them... but there could be fines for circumventing the state / federal emissions laws if you get caught.

Also an update..... no CEL light. Just completely vanished.... Wife now has 104k miles on it. The timing issue was resolved months ago (when the notices first came out), and it wasn't until after that (around 90k) that the CEL came on. As I said before.... I cleared the codes with Nissan Consult III, and the CEL light came back on a day later.... did nothing else, and then.... "POOF" CEL light gone, no more errors, and hasn't come back since....

Still mystified...
It will be back. Mine came on and went off for a couple of months. Now it's on solidly.
 
But that looks like 14K between lights. That's gotta to be more than a few months.
14K?

My Bank 2 CAT went first at 81,000 miles.

Now I'm at 91,000 and SES light is on (but has gone off and on) for Bank 1 CAT.
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Fixed Cat

I have a 2012 QX56 with 104K miles. It threw a P0430 a month or so ago. I reset it once with my scan tool. Of course, it came back once all the parameters reset. After getting a quote for $2,000 to replace Bank 2, I looked at this thread.

Somebody said put a can of Seafoam into a half tank of gas and drive it like you stole it. He got ridiculed and many pooh, pooh'd his solution. I figured, what do I have to lose. So, I bought a can of Seafoam for $7.99, dumped it in the fuel tank and drove it like I stole it. I mean, manual-shift-at-red-line beat on it, repeatedly. The light didn't go away... until I got back in it later and started it up. BINGO, no CEL.

Maybe it will last, maybe it won't. The bottom line is this. The QX56 SUV is an INFINITI performance vehicle. Between trips to the grocery store and the soccer field, put the pedal to the metal and let it fly some. Treat it with a can of Seafoam every 3 months or so. For now, I am going to get the emissions test to PASS and bank the $2,000.
 
Everyone tries the seafoam trick.

Everyone eventually relents that it doesn't work.

Maybe you'll be different though. Here's hoping so.
 
I'm thinking of doing a full exhaust with headers. Any suggestions on a 2011 2wd qx56?

Has anyone been able to install aftermarket headers that have no cats and a full exhaust?

This may be an option to others. Just went with a full header to exhaust setup with tuning from http://www.cajunbpipes.com/Performance-Packages.html

Will let everyone know how it turns out :)
 
We have a 2012 QX56 AWD with 116k miles. Out of curiosity, has anyone that did the DIY or dealer/muffler shop replacement in this thread ever look inside the old cats and compare with the new? Were they clearly bad or “eaten out”? Been driving with the CEL on now with the same code for more than 20k miles. Car doesn’t seem to drive badly and no noticeable fuel economy issues. My mechanic checked the cats and sensors and said “he would love to take my money” but I’m good faith he couldn’t because my cats are “not bad”. Tried the cataclean and no change. Haven’t tried the Seafoam yet.

Okay, so my 2012 QX56 has 82K miles on it. CEL light has been on for months, but the Infiniti dealer isn't convenient and I thought I had read that if the CEL light isn't blinking, then it isn't serious just yet, but still should be looked at.

Took the vehicle in finally a few days ago. The guy basically told me both cats were bad and the cost was $5100......I don't know much about cars, but this seemed absurd for a "well respected" luxury vehicle that hasn't even hit 100K miles. I basically told then, "uh-no thanks". I called my mechanic who could do it for about $3200k. Same parts, just absurd labor rates from Infiniti. If that doesn't tell you how much a dealership overcharges for their labor rates, then by all means, have the dealership work on your vehicle(s).

So I'm making this story longer than necessary, but I ran across a guy who recommended 2 cans of seafoam and some "intense" driving on this thread. I figured what's $15 for two cans versus $3200-$5100? I had a 500 mile round trip road trip coming up, so I figured, now is as good a time as any. Added two cans of seafoam to the my gas tank (tank was half full). I'm guessing two cans of this stuff to a half tank might increase performance? Regardless, that's what I did. Drove it pretty much 85-95 MPH round trip. Well what do you know, the CEL stopped lighting up......after only a few hours. I didn't even need to reset the codes, it just went away. It's been a few days and still nothing. I'm keeping my fingers crossed, but I wouldn't do anything other than add two cans of seafoam before paying anything to anybody.

Just my two cents.

I searched this thread and couldn’t find any updates with your situation. Any update Brooklyndodger?

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We have a 2012 QX56 AWD with over 116k miles. Out of curiosity, has anyone that did the replacements in this thread ever look inside the old cats and compare with the new? Were they clearly bad or “eaten out”? Been driving with the CEL on now with the same code for more than 20k miles. Car doesn’t seem to drive badly and no noticeable fuel economy issues. My mechanic checked the cats and sensors and said “he would love to take my money” but I’m good faith he couldn’t because my cats are “not bad”. Tried the cataclean and no change. Haven’t tried the Seafoam yet.

Also, has anyone tried the O2 sensor hack with the spark plug anti-fowlers? Saw several videos on YouTube posted by shade tree and certified mechanics that claim it worked.
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We have a 2012 QX56 AWD with over 116k miles. Out of curiosity, has anyone that did the replacements in this thread ever look inside the old cats and compare with the new? Were they clearly bad or “eaten out”? Been driving with the CEL on now with the same code for more than 20k miles. Car doesn’t seem to drive badly and no noticeable fuel economy issues. My mechanic checked the cats and sensors and said “he would love to take my money” but I’m good faith he couldn’t because my cats are “not bad”. Tried the cataclean and no change. Haven’t tried the Seafoam yet.

I have changed both catalytic converters on my 2012 QX within 10,000 miles of each other. I did look at the inside of my first bad catalytic converter very well. It was exactly like the inside of the new one. The old one just looked older and the new one looked new.

Now to a different story.

I own a 2008 Nissan Maxima (the most reliable and trustworthy car I have ever owned! Never left me stranded ever! I just love this car!) with currently 225,000 miles on odometer that I bought brand new in 2008. This car had the check engine light come on at about 160,000 miles for one cat and then soon it was reading for both cats. But my car was driving fine. So I bought all parts to change the cats but I noticed that the performance of my car got better with the check engine light on. I am not kidding you that when I step on this thing to get on the freeway or demand instant power to pass up cars, it would respond immediately and with speed!

I drove my Maxima for about 35,000 miles like that which lasted me about 2 years. Then I decided it was time for me to go and change the parts for the brand new parts I have been keeping for almost 2 years. Well, they changed my cats and my mechanic was lost for words when he pulled out the bad cats. All the inside of my bad cats were hollow. All the honeycomb has been melted somehow and maybe disappeared or went out the exhaust? I don't know.

But my mechanic said this is weird and that he is very surprised my car had not basically stalled and failed any time before bringing it to get it changed. He said there is no way my car can burn the honeycomb and shoot it out through the exhaust. So he said I must have some pieces of metal somewhere in my car and it may ruin my car someday soon. Well, that was at 190,000 miles. He changed the cats and he said I needed to change some other part where he suspects the pieces have gone into. I said no thank you, I am sure my car is using it as "nitro" to go as fast as it is going because this Maxima is FAST!

That was at 190,000 miles when my mechanic said I should change the other parts that may be having pieces from my bad catalytic converter honeycomb. I refused. Today, my car has 225,000 miles and I still drive it like I stole it! And I will praise my Maxima any day about how reliable this car has been to me. It is my most reliable car and the car I have owned the longest so far.

So, you can drive your Infiniti like that. It may burn up the honeycomb like what happened to my Maxima.

Anyone can keep on driving a car with a bad catalytic converter. I just hear that over time the cat may become clogged up and you lose a engine! So, not wise to keep on driving a car for long with check engine for failed cats.

So drive your QX, but I will advice you to save money to get those cats changed pronto! Except you want to chance it like I did with my Maxima. But I do not mind if my Maxima dies today and can never start again for it has really served me already and I have had my money's worth. But I will not be pleased if something like that happened to my QX that because of faulty cats, it ruins the engine.
 
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I have changed both catalytic converters on my 2012 QX within 10,000 miles of each other. I did look at the inside of my first bad catalytic converter very well. It was exactly like the inside of the new one. The old one just looked older and the new one looked new.

Now to a different story.

I own a 2008 Nissan Maxima (the most reliable and trustworthy car I have ever owned! Never left me stranded ever! I just love this car!) with currently 225,000 miles on odometer that I bought brand new in 2008. This car had the check engine light come on at about 160,000 miles for one cat and then soon it was reading for both cats. But my car was driving fine. So I bought all parts to change the cats but I noticed that the performance of my car got better with the check engine light on. I am not kidding you that when I step on this thing to get on the freeway or demand instant power to pass up cars, it would respond immediately and with speed!

I drove my Maxima for about 35,000 miles like that which lasted me about 2 years. Then I decided it was time for me to go and change the parts for the brand new parts I have been keeping for almost 2 years. Well, they changed my cats and my mechanic was lost for words when he pulled out the bad cats. All the inside of my bad cats were hollow. All the honeycomb has been melted somehow and maybe disappeared or went out the exhaust? I don't know.

But my mechanic said this is weird and that he is very surprised my car had not basically stalled and failed any time before bringing it to get it changed. He said there is no way my car can burn the honeycomb and shoot it out through the exhaust. So he said I must have some pieces of metal somewhere in my car and it may ruin my car someday soon. Well, that was at 190,000 miles. He changed the cats and he said I needed to change some other part where he suspects the pieces have gone into. I said no thank you, I am sure my car is using it as "nitro" to go as fast as it is going because this Maxima is FAST!

That was at 190,000 miles when my mechanic said I should change the other parts that may be having pieces from my bad catalytic converter honeycomb. I refused. Today, my car has 225,000 miles and I still drive it like I stole it! And I will praise my Maxima any day about how reliable this car has been to me. It is my most reliable car and the car I have owned the longest so far.

So, you can drive your Infiniti like that. It may burn up the honeycomb like what happened to my Maxima.

Anyone can keep on driving a car with a bad catalytic converter. I just hear that over time the cat may become clogged up and you lose a engine! So, not wise to keep on driving a car for long with check engine for failed cats.

So drive your QX, but I will advice you to save money to get those cats changed pronto! Except you want to chance it like I did with my Maxima. But I do not mind if my Maxima dies today and can never start again for it has really served me already and I have had my money's worth. But I will not be pleased if something like that happened to my QX that because of faulty cats, it ruins the engine.

Wow! What an awesome story and thank you for sharing. We will be officially done with the 56 tomorrow. Trading for a 2016 QX80. We read that Infinity didn’t correct the cat issue until the 2014 model year. So very disappointed with how they dealt (or didn’t deal) with this issue but not enough I guess to buy something else ;) Good luck my friend. I look forward to continuing to read your future posts. This forum is very informative and pretty darn awesome.
 
I just bought my 2nd QX. 1st was a 2004 and it treated me very well The cats went out at about 135,000 miles - I did the research and instead of replacing them, I drove it until I traded it with 187,000 miles. I am not condoning this, just stating my experience.

My question is . . . Are you individuals with Cat issues using premium?
I ask because I only used premium in my 2004 every 4th or 5th fill-up. Could that be the reason the cats went out?
Any input would be helpful - I really don't want to have the same issue with my 2012.
THX
 
you SHOULD be using high test/premium petrol in this engine. if you are not, the computer will adjust but performance will be poor and you could have other issues (pinging, etc). also if you are using cheap/non top tier petrol you could also get issues.

nissan armada was kinda known for cat issues, and that car recommended regular petrol, so i dont think JUST using regular petrol would cause you issues.

my opinion and im not a mechanic.
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I just bought my 2nd QX. 1st was a 2004 and it treated me very well The cats went out at about 135,000 miles - I did the research and instead of replacing them, I drove it until I traded it with 187,000 miles. I am not condoning this, just stating my experience.

THX

I had the same experience like you. It happened to my 2008 Maxima. My cats went out at about 140,000 miles. I drove it for over 2 years like that and replaced the cats when my car had over I think 180,000 miles.

My question is . . . Are you individuals with Cat issues using premium?
I ask because I only used premium in my 2004 every 4th or 5th fill-up. Could that be the reason the cats went out?
Any input would be helpful - I really don't want to have the same issue with my 2012.
THX

So now you have a 2012 QX56. I drive a 2012 QX56 also.

How many miles do you have on yours? Mine now has 127,000. I use premium more often than I use regular. So, it is a mixed for me. And I have had both my cats go bad within 10,000 miles of each other and I had to replace them both with OEM.

Inifniti recommends premium for thi car, but I dought regular folks who buy this car used will always put premium in it. Many more people probably use more of regular than premium.

You can decide and be using only premium, but that does not necessarily guarantee you will not have a faulty cat. Or you may never even have a faulty cat. Who knows? Stick to the recommendation from Nissan for your own peace of mind. Some of us change things some times.

Like recently for me, I just started using 0W40 for my oil change in my QX and Nissan. But Nissan has no where in it books that it recommends this oil for my QX or my Nissan. But I will tell you that both cars are still driving very fine. And both cars seem to truly like the oil. I will be sticking with it until I have a reason to change again.
 
I have almost 84,000 on it.
I guessed that it's kind of a crapshoot on the Cats, but thought I'd ask if using premium vs regular could be a contributing factor.
I do plan on using premium (non-oxy when I can) and letting the wife take it on her longer commute a few days a week. I only have a 3 mile commute, so it barely gets warmed up. I've read that can be an issue as well.
 
Has anyone tackled replacing the cat’s and O2 sensors themselves. If so, please share.
 
Alternative P0420 and P0430 solution

Hey everyone I just want to comment on my experience with the code P0420 and P0430. I did a lot of research before coming to the conclusion that I would try cleaning them before replacing them. There is a video on youtube that I followed to perform this fix. The guy on youtube use a can of spray seafoam, but instead of spraying it in the throttle body he removed his 02 sensors and sprayed directly into the catalytic converter. Long story short it solved his problem.

Like most on here, I got the code P0420 and P0430. The difference I experience was my check engine light would come on for a cycle and then go off, but on my Tmobile sync up drive it would always show the DTC even if the check engine light was not on. I decided today was the day to try what I have learned. Tools that I used were 10 mm wrench, a star screwdriver, a flat head screwdriver, 3-ton jack stands, rapid pump jack, Impact Gun to take off lug nugs, an oxygen sensor socket and a Foxwell 624 Auto pro scanner (which is a must for our trucks, one day I will do a review about this for our trucks).

First thing, is to plug your scan tool to take current values of the Bank1 Sensor2 and Bank2 Sensor2 readings. Make sure the scan tool you are using can read and graph. Write them down to compare with after cleaning. What you are looking for is somewhat of a consisted pattern or volt reading.

The second thing you want to do is put on the emergency brake and jack up the truck and put jack stands on either side. Take both of the tires off and wheel well(trust me it is much easier this way). On the driver side, the location of the Air/Flow sensor is located behind the bracket that holds the brake lines.

You can use a 10 mm socket to loosen the bolt so that you can monuver it out of your way if you wish, I just left mine alone and was able to get to the sensor with extensions. I unplugged my sensor from the wheel well given that I removed the wheel well cover. The passenger side is a little different, but way easier than the driver side. Once you remove the wheel well the Air/ Flow sensor is accessible. You still need an extension, but it is not that hard at all to unplug and remove.

ONCE THE SENSORS ARE REMOVED, BE CAREFUL NOT TO DROP THEM!!!!! When I removed my sensor they were very dirty, but I elected not to clean them for two reasons. One they still work perfectly according to the scan tool and two I have heard too many horror stories about people messing these things up. If it is not broken don't touch it. At this point, you are ready to spray the Seafoam into the catalytic converter.

The Seafoam I used comes with a little red spray nozzle perfect for this job. Spray as much as you think you need to get the job done. I should have mentioned this earlier, you can pretreat your truck by adding some seafoam additives to the tank prior to doing this and using premium gas leading up to this. Once you have sprayed what you feel like is enough, it is time to reinstall your Air/ Flow sensors (at this point if you are replacing the Air/ Flow sensors, I would use the old one's fist until the job is done then replace them), for this step hand tightening is fine.

Before starting the vehicle make sure everything is clear, and that you are in a well-ventilated area because there will be a lot of smoke. Hook up the scan tool and look for these values Cat Temp bank 1, Cat Temp bank 2 1, Oxygen sensor bank 1 sensor 1, Oxygen sensor bank 2 sensor 1, and engine rpm. Start the truck and try to hold your rpm's at 2500. Hold until you have cleared the smoke. On the scan tool, you should see the temperature for the catalytic converter rise and your oxygen sensor start leveling out. Once all the smoke has cleared, you can shut off the truck. At this point, you can let the truck cool a bit and repeat or if you feel that was enough cleaning you can start to put everything back together in the reverse order. Remember to tightening up your Air/ Flow sensors before putting things back together if you are not replacing them with new ones.

After you button up everything clear all codes and take a good 45 min drive or longer at highway speeds to burn any residue that might be left. When you get home, check to see if there are codes. If not, sit down have a cold one and look out on GOD's green earth, because my friend you have fixed your problem with a 10.00 can of seafoam...lol

P.S. The scan tool that I used is Auto Pro 624 and far as I know it is a professional level scanner. It basically scans everything ECM, TCM, and all sensors. It is basically on par with the consult 3, of course, nothing will replace a dealer level scanner, but for the price, it gives you a lot of information. No more guessing. I am not a spokesman for this company, I just own the tool and wanted to pass along my experience with it on our trucks
 

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Hey everyone I just want to comment on my experience with the code P0420 and P0430. I did a lot of research before coming to the conclusion that I would try cleaning them before replacing them. There is a video on youtube that I followed to perform this fix. The guy on youtube use a can of spray seafoam, but instead of spraying it in the throttle body he removed his 02 sensors and sprayed directly into the catalytic converter. Long story short it solved his problem.

Thanks for taking the time to do that write up! How many miles have you gone since performing this cleaning? You code reader has not seen one cat code since doing this?

I started seeing the cat code at a little over 80K miles and now I'm at 135K.

Later,
pjdavep
 
Thanks for taking the time to do that write up! How many miles have you gone since performing this cleaning? You code reader has not seen one cat code since doing this?

I started seeing the cat code at a little over 80K miles and now I'm at 135K.

Later,
pjdavep

You're Welcome! Any way to save us money and keep enjoying the rides that we purchase...lol. Since performing this I have gone about 200 miles or more and MIL light is still off. I will update in a week or so if this is still the case. Keep in mind I suspect I will probably have to do this again before I really clean them out...lol. But yeah, it has not thrown a code since doing this.

P.S. I know my cat on Bank 2 was dirtier than the cat on bank 1 so when I performed this I went in with the mindset that I would have to probably perform this on that cat multiple times before I really clean that one out. Word of advice that I did not mention in the original post is that it is probably a good idea to also replace the O2 sensors on the downstream for good measure and make sure that whatever cause the cats to go bad in the first place is ratified before performing this maintenance. I hope this helps.

Hey, I decided to take some more photos when I got home today of the scan tool hooked up to my truck. The scan tool shows no current or pending DTC's at this time, which is wonderful! I did a quick read of the Oxygen sensors Bank 1 A/F, Qxygen Senor 2 and Bank 2 A/F, Qxygen Senor 2. All look to be within spec. My only concern at this point is the reading from the Bank 2 Qxygen Senor 2 it is still a little jumpy at times, which could indicate that it probably could stand another cleaning. At this point, if it gets bad enough to throw a code again I will probably clean and replace the sensor first before heading down the road of outright replacement. Again as of right now, everything is within limits and I have no codes. Wooohooo!

Again I can't stress enough of having a good scan tool is, because without it you are at the whim of ours telling you to replace something that might not need a replacement at that time. For me, replacement means a whole new exhaust system because I have rusty bolts that have likely sized so if this can get me by or anyone else until that time of total replacement heck I am all for it :).

Glossary:

Cats - Catalytic Converter
A/F - Air/ Flow

Photo's at the bottom:

1 - Shows current DTC's or Pending DTC's
2 - Shows all the values that concern the Cats sensors.
3 - Shows Bank 1 A/F, Qxygen Senor 2 and Bank 2 A/F, Qxygen Senor 2 (if you notice there is not much moment and that is what you want).
4 - Shows Bank 1 A/F, Qxygen Senor 2 and Bank 2 A/F, Qxygen Senor 2 (Like I said it is a little jumpy at times, but it is within spec.).
5 - Shows Bank 1 A/F sensor, and Bank 2 A/F sensor and if you are wondering there are supposed to be this active if they are not, replace them.
 

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2012 QX56 purchased this Dec for my wife, 58k, on the 700 mile drive home from L.A. it threw a CEL, took it to Auto Nation Mercedes dealer upon arrival home ( purchased from Auto Nation, 4k 90 day warranty) cleared and said it was a Catalytic Converter code. I then took it next door to Infiniti dealer and they said they would take care of it if it appeared again. It appeared this week, took it to Infiniti (60k miles) both CAT's need to be replaced and will be replaced at no charge along with a rental car. I'm so happy this happened now, not sure about the CAT's in the future!

Anyone know what you think the warranty will be on the new CAT's? I'll ask the service adviser when I speak with them next week.
 
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