Thank you for this video. I kept getting the P0420 code on my 2014 QX and it would come back about two weeks after I would clear it. I was told by mechanics it's for sure the catalytic converter. I put cat treatment in my fuel several times and I would still get the code. I changed the upstream driver side O2 sensor (Denso from Rock Auto) and that permanently removed the code. I was also able to get my braker bar on the O2 sensor socket from above and didn't have to take off the wheel. You just have to try several different positions on the socket. Great video and definitely change your O2 sensor as a first measure instead of spending $2,500+ for a new cat which is supposed to last the life of the vehicle. My QX only has 74,500 miles.

Thanks for this video. Man I wished it this simple when I tried mine. I used a different O2 sensor socket and had no luck and ripped my wires out. O2 sensor didn’t come out.

This video was helpful! My 2012 qx56 has been causing me trouble. Check engine light came on. Went to Autozone to scan it, and those two codes popped up saying that converter bank 1 and 2 sensors are the problem. Took it to the neighborhood shop, and he recommended changing the trottle body and air intake sensor. Did that, and it ran good for a while, but the codes came back. Finally, we decided to take it to the Infiniti dealership because they must know what the problem is. They diagnosed it as being a timing chain issue. Never mentioned anything about the converter sensor problem. I asked them if they checked the converter, and their response were, " No codes popped up about the converter. Priced me $6k to replace my timing chain kit with new spark plugs. Of course, I decided to seek a second opinion. Had to pay $500 for a bogus diagnosis. Drove the vehicle of the lot, and before tonight is over, the check engine light reappeared with codes p420 and p430. The Autozone scan tool says replace catalytic converter with OE Catalytic converter. So, have you heard anything about the timing chain needing to be replaced with this kind of issue?

The best to remove bank one sensor 1 and bank 2 sensor one is remove the front wheels, pull back the plastic panel hold it with a bungee cord, you should be able to access it from there. What he saying is also correct.

Thank you for the info on how to replace that bank 1 sensor and now I will replace the part in my 2012 QX56. Awesome job.

This is a great video, thanks for making this. The offset socket and impact wrench were critical for me. Dealer wanted $605 to replace it.

great video, thanks. My 2014 Infiniti QX80 is having this exact problem. I appreciate the close up views and clear instructions.

Great video, thanks. I have a 2013 Infiniti QX56 with the same codes, actually both sides. I appreciate the close up views and clear instructions.

Great video! Thanks for showing me an easier way to replace the 02 Sensor!

Based on the comments here I think there is high chance of cracked manifold for the 2nd gen QX(2011+). Search "QX56 cracked manifold" you'll see details. Looks like they didn't change the faulty design of cat converter/exhaust header.

My 2014 QX80 threw that code at 72k miles. I replaced all 4 o2 sensors for good measure. Now at 78k miles, the code is back.

This video saved me 200 dollars. Thank you!

Good work man. Nice job using the stapler.

Thank you so much for an awesome video. It is so easy to watch because of your calm narrative and not skipping any steps. I am having the same issue with P04020 and P0430. I replaced the downstream O2 sensors (both codes came back), so today I want to replace both upstream sensors. Your video will be super helpful in doing so. What I would like to know is if the error codes came back? Mine come back after about 370 miles of erasing them. I hope the problem goes away with replacing the upstream sensors. I only have 89000 miles on my QX56 and the dealership says I need to replace the catalytic converters which is a $5000 job at Infiniti.

Exelente video, muchisimas gracias por tu valiosa aportacion!!

This is an awesome video. Thank you so much for making this!!!

Nice .... I went to the dealership the first time and they hit me for 2k. They """REPLACED""" the cats. 8 months later the code has returned. I don't think they replaced the o2 sensors

My car also having same issue.. can you fix it? Please let me know..

My car also having same issue.. can you fix it? Please let me know..😢

I am still watching your video, but I'm worried that an UPstream 02 sensor could set a P0420 fault code.

So I’m not sure what upstream and downstream are. I’ve only seen them referred bank 1 or 2 and sensor 1 or 2. Can you clarify? Great video btw, thanks!

Great video sir. Have you done the down stream one yet? I'm having the same issues and have purchased both up and downstream sensors. I have yet to change them.

I have QX56 2013 and i have 2 codes P0133 and P0430 , if i replaced the o2 sensors will there be chance for the code to go away because there is a black smoke for the exhaust and very bad feul range full tank run around 200miles??

Thank you!

I have the older model and tried Walker o2 sensors. They didn't last. The codes p0153 and p0133 are back.

Have you done a Vid on changing the Upstream Cats? Both of them? I think I need to on my 2011 Infiniti QX-56. Or just bring it to you 🤷🏿 to change

My armada has the p0420 and p0430 and when ran a while will stall. Is that most likely the cats? On both sides?

Hi. Has the check engine light stayed off and it’s still code free? Thx.

What if both codes at same time/both banks

I have P0175 B2 code , What that mean?

What kind of driving issues were you having before you changed