[Giants10]

I been fixing all kinds of things on my 2011 Pilot lately. Still better then payments, right? So I know it's probably catalytic converter that I need to do, but wanted to me sure it wasn't 02 sensor. I used blue driver scan tool. It's only showing 2 oxygen sensors. Bank 1 and 2 sensor 2. That doesn't make sense to me. Shouldn't I have one on both downstream and upstream? Also, being sensor 2, both of those are post cat, so shouldn't the readings be more stable? I included the picture. The p0420 is saying bank 1. Which cat is that? Thanks for any help with this.

 

[killster2smallbox]

passenger side cat needs to be replaced (behind the passenger side wheel). i have the same issue and have yet to complete the work required to change it. i did try and run some cat clean / premium gas / injector cleaner to no prevail, i purchased a new o2 sensor for the intake and output of the cat but only have changed one so far. i also purchased a defouler and was tempted to try that before changing the cat. ;( annoying

 

[AVC]

From your live data captures, the rapid variations in B1S2 output are causing the P0420. The cat has dropped below the prescribed threshold for oxygen storage. There are 02 sensor "cheaters" that may eliminate the code. Otherwise a new cat. Bank1 is on the cabin side.

And yes, there are upstream sensors. You may have to dig a bit on your scan tool to seem them. They may not be called "02" but "A/F" or something else

 

[Giants10]

I'm

From your live data captures, the rapid variations in B1S2 output are causing the P0420. The cat has dropped below the prescribed threshold for oxygen storage. There are 02 sensor "cheaters" that may eliminate the code. Otherwise a new cat. Bank1 is on the cabin side.

And yes, there are upstream sensors. You may have to dig a bit on your scan tool to seem them. They may not be called "02" but "A/F" or something else

I just ran the scan tool again and now p0430 is showing too. What are the chances both cats go?

 

[killster2smallbox]

I'm


I just ran the scan tool again and now p0430 is showing too. What are the chances both cats go?

well you can start with new spark plugs, oil and some injector cleaner and premium gas? i didnt see anything about what you have tried to remedy the problem and of course my advice is from a non expert newbie ;P (replaced my spark plugs and the rest and still had the error but only in one bank. )

 

[AVC]

I just ran the scan tool again and now p0430 is showing too. What are the chances both cats go?

Well, they are the same age, so I suppose the chances of both cats showing efficiency issues isn't outrageous, although bank 2 live data looks decent under whatever conditions to snapped that. Cruising? At idle?

Is there freeze frame data for 0420 and 0430?

The PCM runs a fairly elaborate rich, then lean routine @ cruising before setting those codes. Maybe @Slvr7 has seen efficiency codes where the cat wasn't dodgy.


Otherwise, what are total fuel trims at idle and cruising?

 

[Giants10]

Well, they are the same age, so I suppose the chances of both cats showing efficiency issues isn't outrageous, although bank 2 live data looks decent under whatever conditions to snapped that. Cruising? At idle?

Is there freeze frame data for 0420 and 0430?

The PCM runs a fairly elaborate rich, then lean routine @ cruising before setting those codes. Maybe @Slvr7 has seen efficiency codes where the cat wasn't dodgy.


Otherwise, what are total fuel trims at idle and cruising?

Well, they are the same age, so I suppose the chances of both cats showing efficiency issues isn't outrageous, although bank 2 live data looks decent under whatever conditions to snapped that. Cruising? At idle?

Is there freeze frame data for 0420 and 0430?

The PCM runs a fairly elaborate rich, then lean routine @ cruising before setting those codes. Maybe @Slvr7 has seen efficiency codes where the cat wasn't dodgy.


Otherwise, what are total fuel trims at idle and cruising?

This was while driving earlier today. Now the p0340 code is out. That one keeps coming on and off. P2040 is constant.

 

[bzwyatt]

Is it just that I never had these so I never noticed other people posting about these codes, or is it that all the '09-'12s are ten+ years old and needing the same stuff at the same time?

Anyway my '09 just had 0430 come on and off too. I am researching threads, and if I do work and have info to share, I will.

 

[AVC]

Both after-cat sensors look very active; not a good thing. Bank 2 has slightly less severe swings, which is why the P0430 may come and go.

Did you find the before-cat sensor live data? Comparing B1S1 to B1S2 and B2S1 to B2S2, best reveals a good cat vs marginal vs bad cat. The after-cat graph should move very lazily as compared to the before-cat. The exception is when you lift-throttle, where both sensors will usually peg lean quickly.

 

[Giants10]

Well, they are the same age, so I suppose the chances of both cats showing efficiency issues isn't outrageous, although bank 2 live data looks decent under whatever conditions to snapped that. Cruising? At idle?

Is there freeze frame data for 0420 and 0430?

The PCM runs a fairly elaborate rich, then lean routine @ cruising before setting those codes. Maybe @Slvr7 has seen efficiency codes where the cat wasn't dodgy.


Otherwise, what are total fuel trims at idle and cruising?

I just went for a drive. It stayed mostly around .500 volts, going as high as .800 and as low as .300

idling it's staying around .6-.700 mostly. If I give it some gas it drops to as low as .020. Both sensors are pretty much identical in what they are doing.

 

[Giants10]

Both after-cat sensors look very active; not a good thing. Bank 2 has slightly less severe swings, which is why the P0430 may come and go.

Did you find the before-cat sensor live data? Comparing B1S1 to B1S2 and B2S1 to B2S2, best reveals a good cat vs marginal vs bad cat. The after-cat graph should move very lazily as compared to the before-cat. The exception is when you lift-throttle, where both sensors will usually peg lean quickly.

Forr some reason it says not supported with this vehicle. I can only get bank 1 and 2 sensor 2. I bought an inferred tool from Amazon today so I can check heat from Cats Just waiting for that.

 

[AVC]

Both sensors are pretty much identical in what they are doing.

"pretty much identical" may be the difference in always setting an efficiency code in one bank, and intermittently in the other.

None of the Honda manuals I have provide the exact criteria to flag low cat efficiency, bu it does suggest "fuel quality" can be a factor. It doesn't spell that out, so not sure what type of fuel contamination or deterioration might cause unhappy cats.

Otherwise, we'll have to assume the PCM determined correctly. As a DIY, the "ahah" is comparing the upstream to downstream sensor activity which gives insight to what the PCM is flagging as "bad".

As for cat temps, not sure what "normal" is for the Pilot in park at XX RPM --never measured.

 

[AVC]

I was reading another thread you posted onto, where you state your Pilot has never had a VCM disabler on it. A side effect of of VCM shutting off cylinders in 2 and 2.5 Gen Pilots is excessive oil consumption, which eventually kills cats.

It is possible (no certainty) that a few thousand miles of running (like some 70mph long cruises) with VCM disabled might burn off or expunge enough carbon in the cats to raise the efficiency above code thresholds.

 

[Giants10]

From your live data captures, the rapid variations in B1S2 output are causing the P0420. The cat has dropped below the prescribed threshold for oxygen storage. There are 02 sensor "cheaters" that may eliminate the code. Otherwise a new cat. Bank1 is on the cabin side.

And yes, there are upstream sensors. You may have to dig a bit on your scan tool to seem them. They may not be called "02" but "A/F" or something else

I do see 02

I was reading another thread you posted onto, where you state your Pilot has never had a VCM disabler on it. A side effect of of VCM shutting off cylinders in 2 and 2.5 Gen Pilots was excessive oil consumption, which eventually kills cats.

It is possible (no certainty) that a few thousand miles of running (like some 70mph long cruises) with VCM disabled might burn off or expunge enough carbon in the cats to raise the efficiency above code thresholds.

I ordered the vcm today and also pcv valve. Knocking out Nails list. I'll go for a long drive sometime soon too! I was suppose to get it inspected last month. So I got to get on this.

 

[Slvr7]

Honda seems to be very accurate with 420/430 codes. I have yet to see either replacement of the a/f sensor or s2 sensors fix them. Normally the customer returns after they try that and it doesn't work, luckily we only do 3 or 4 cats a yr.

 

[Nail Grease]

So far, with my maintenance list plus disabling the VCM, it has permanently ended my P0420 P0430 codes.

 

[undivide]

running a couple tank fill ups of gas with seafoam and replacing the AF sensor as well as the secondary 02 sensor for the rear cat fixed my 420 code. then again my code only appeared during the cooler winter months and went away in the summer. verified both cats functioning identical based on temp readings with an IR temp scanner after fully warmed up engine being recently driven.
oil contamination, coolant contamination, routinely filling up with low quality gas and using low quality oil and just general wear and tear that is associated with old age can contribute to these failures. just like with misfire codes, the code doesn't tell you "hey dummy replace this and you'll be good as new"
it requires some degree of troubleshooting.
if nothing else, working your way up the parts chain from least expensive to most expensive is always an option however I wouldn't go putting all new sensors, plugs, injectors, and a cat on ... only to discover there is coolant entering that is contaminating everything.

 

[Nail Grease]

I‘ve never bought a new MAF for any vehicle. The one on the 301k mile 2012 Crosstour is the original. You must be careful when cleaning. Never hold upside down when using MAF cleaner or electronic cleaner. You don’t want cleaning solution up inside the covered portion of the sensor. Spraying the visible electrodes with a few short burst only.

 

[killster2smallbox]

running a couple tank fill ups of gas with seafoam and replacing the AF sensor as well as the secondary 02 sensor for the rear cat fixed my 420 code. then again my code only appeared during the cooler winter months and went away in the summer. verified both cats functioning identical based on temp readings with an IR temp scanner after fully warmed up engine being recently driven.
oil contamination, coolant contamination, routinely filling up with low quality gas and using low quality oil and just general wear and tear that is associated with old age can contribute to these failures. just like with misfire codes, the code doesn't tell you "hey dummy replace this and you'll be good as new"
it requires some degree of troubleshooting.
if nothing else, working your way up the parts chain from least expensive to most expensive is always an option however I wouldn't go putting all new sensors, plugs, injectors, and a cat on ... only to discover there is coolant entering that is contaminating everything.

well to be fair replacing a cat is cheaper then the sensors (more labor but the parts are cheaper) im still sitting with a 0420 but not in any rush to replace the cat since i would rather go to six flags or seaworld or go camping or.... on my day off then change the cat i have tried good gas, changing the plugs, (needed to anyway since they might have been oG with 150k) use Costco synthetic oil usually but seems like its pretty decent stuff, i have yet to get under the pilot with a IR scanner, sounds like something very simple, have yet to monitor the sensors as the Op did with a scanning tool (just got a 35$ one from amazon have yet to plug it in kw080 or something)
not sure how coolant would enter my cat im 100% sure that isnt the case.

 

[undivide]

monitoring sensor data is useless unless you are 100% sure the sensors are reporting accurate data.
I would be very hesitant to also replace something without knowing exactly what caused it to fail.
You could end up ruing a brand new $300 (not cheap) catalytic converter because of another underlying issue.
and if your catalytic converter is cheaper than BOTH upstream and downstream sensor then it's probably not good quality and will most likely end up failing and throwing more emission codes.