Help With P0430 "Catalyst Monitor Bank 2" Test Failed

I have been getting a P0430 check engine light for some time now. Until recently I have just been resetting the light using the Torque App on my phone with a bluetooth adapter. Lately I've been noticing my fuel mileage has been crap so I decided to look into it.

This passed weekend I did some maintenance and reset the code, I cleaned my throttle body, MAF Sensor, new air filter and ran half a can of sea foam in the throttle body vacuum line while putting the left over in a half tank of premium.

The light hasnt came back yet, but I checked with my phone and it says that its pending P0430 again, I checked the test that caused this and it was a Catalyst Monitor Bank 2 test that failed.

I am also exceeding the amount of miss fires in some of those test, I have posted screenshots. I replaced my spark plugs about 30,000 Kilometers ago, so I cant see them being bad. I am guessing this is because of the sea foam still in the gas???

Any ways I am assuming I have an exhaust leak or a bad cat, but I could be wrong. Has anyone seen this failed test before?

 

I've had this code for the last two days as well, and was literally about to start a new thread when yours popped up. I know nothing about exhaust systems or catalytic converters. I've tried researching things here, but am still dumbfounded.

There was this guy's thread but it seemed he had been driving with it for possibly thousands of miles, and spent a lot of money I don't have to solve his problem.

There was also this guy who in a separate post a few month's later said he sold his truck because as he dug deeper, more and more things seemed to be wrong with it....

I will try to figure out how to replace the O2 sensors, as switching bank 1 and bank 2 seem to indicate if the problem is in the sensor itself or somewhere else in the cat, but again I'm completely in the dark here when it comes to exhaust. Everything I know about trucks, I've learned through mine because of trial and error. So until now I've never had to think about catalytic converters and stuff... I guess this is just another annoying educational opportunity.

Looking forward to hearing from our more knowledgeable members!

 

well when I ran graph tests on my 02 sensors they didnt seem to be dead or lazy, so I am assuming its my cats, which is a common problem with these trucks, if it is the cats, Im going to attribute it to ethanol in my gas

If it is the cats I have a few options,

1. URD 02 sensor simulator
2. URD 02 sensor simulator with JBA/DT long tube headers (Dont really want to lose the low end power though as I only drive in lower rpm)
3. JAB/DT Short headers with after market cats
4. Stock replacement manifolds/cats (not gonna happen with how much they cost)
5. Walker/Magnaflow manifolds/cats (Probably the direction Im going to go with)

First things first I am going to have my exhaust checked for any leaks, a bad gasket or a broken pipe somewhere can cause this issue, as well as some peoples 02 sensors have come loose and the bolts have actually fallen out, which can cause this problem as well.

 

Just stopped by my mechanics shop, he doesnt think there is a leak as he said it would be easy to hear. I am going to swap my 02 sensors tonight and see if the error switches to the other bank. I want to eliminate the 02 sensors.


I am looking at getting evan fischer manifolds, does anyone have any experience with them? They are a newer company.

 

I saw somewhere that the wiring harnesses are different lengths for bank 1 and 2, and that one won't fit in place of the other. is this true?

 

they definitely have different part numbers, but look the same, so its probably true. Sandman614 had the exact same problem, literally exact and his fix was changing out the manifolds/cats, so I'm guessing this is what I'm going to have to do.

 

Your test output says that sensor 2 is reading *BELOW* the specified range - which would tend to indicate a bad sensor rather than a bad cat.

 

the voltage tests that indicated a bad sensor are passing, this is a different test as far as I can tell.

 

Maybe.

Helluva lot cheaper to change a sensor than a cat.

I think your plan to swap sensors 1 & 2 and see if the error moves is a good one.

 

How many miles are on your truck? My 05 taco had 217k on it when i bought it, and i had the same code. Turns out both cats were completely gone. It sucks that the cats are part of the exhaust manifolds, but you can get good used ones on car-part.com for around 150 per side. Not terrible.. You also get to put on a new exhaust manifold gasket just in case yours is leaking a little bit and making your engine louder. After i replaced mine my engine was WAY quieter. went from sounding like a sewing machine to an awesome almost diesel sound.

Just my experience......

 

so if the exact same code pops up after swapping sensors, what's the next test? Is it guaranteed that the cats are bad and everything must be swapped? or is it possible just one of the cats is bad or something else in the system is causing the code?

 

Instead of swapping sensors, disconnect the exhaust pipe right after the cats and have a look up in there (toward the engine, not toward the back of the truck). If it is empty and hollow, your cats are gone. if you see a white honeycomb/screen right there, then your cats aren't blown out. Not completely at least.

There also are little sensor spacers that you can buy that pull the sensor further out of the exhaust pipe and away from the exhaust fumes, thus not letting the sensor do it's job, thus not setting off your check engine light. If you wanna take the easy way out...

 

I just finished swapping the sensors, resetting the computer and then driving around until the test finished, I got the exact same results. Also the one sensor does have a shorter cable and I had to unmount the connector in order to get it to reach. So considering the other members who have had to replace cats I am going to order some new ones. I do not want to bandaid the fix with an o2 sim or drilled out spark plug foulers. The truck is most likely tuned to have the right amount of back pressure from the cats. Plus like has been mentioned, i do not like the sound of the stock cats.

 

for $360 shipped I can get both replacement manifolds and cats from partstrain.com

http://www.partstrain.com/store/det...verter/REPT960313.html?location=Firewall_Side

http://www.partstrain.com/store/det...verter/REPT960314.html?location=Radiator_Side

If anyone has any experience with this brand please let me know.

 

Rarely is a catalyst monitor failure being caused by something else. The only reason the monitor failed is simply because it has surpassed the threshold (limits) of what the stock PCM has designated for it. The computer determines what that threshold is by taking the information by both front and rear oxygen sensors and comparing the data between the two.

If it happened sooner then later in the mileage spectrum of your car, you might want to look at the underlying causes as to why it failed as early as it did, because if you are not running optimal 14.7 stochiometric ratio during cruise, this is also costing you unnecessary gas mileage. If it failed at high mileage 200K+ miles, time has simply finished your converter off, and will be solved simply by replacing the old one with a new one.

Sorry about the long schpiel of tech info. I hope this helps though, and good luck.

 

I've been running the magnaflows for a couple weeks now and they're doing great. If I remember right I've read that 05 and 06 years had some cat problems. Like it was said, unhook the y-pipe and have a look at the manifold cats(and the rears while your there). Easy to do and that will tell you what and how soon you need to address the issue.

 

I have 130,000 kilometers so approx 80,000 miles, which from reading around on here isnt too uncommon. What is stochiometric ratio?

 

Ive just googled stoichiometry, I wonder if my afe intake that I got rid of had anything to do with it.

 

The intake DOES slightly mess with the Air/fuel ratio in all truth, it will open up airflow some, which in turn causes an imbalance in the AFR because you now have excess air flow in comparison to the original amount of fuel the computer is calculating. The computer see's it as a lean mixture (excessive airflow) and it begins to run improperly and throws the oxygen sensors out of whack.

How many miles did your rig have?

 

80,000 miles

I just found the same cats for $260 on ebay, I think Ill pull the trigger and hopefully they fit alright, seems to be hit and miss with these cats.

http://www.ebay.ca/usr/carpartswholesale