P0430 CEL code Actual Solutions?

[willmtaylor]

Chasing a P0430 CEL code (Catalyst system efficiency below threshold bank 2) popping up every few hundred miles on my 2005 Land Cruiser. I’ve tried a bottle of CATACLEAN that didn’t seem to do much.

I’ve search threads and seen folks suggest a myriad of solutions. My question is, have any of them ACTUALLY worked? Those who have had P0430 (or P0420), what did you do that finally fixed it?

Anyone had success with new MAF sensor replacement? O2 sensor replacement? Miracle in a bottle? “Italian Tune-up”?

Appreciate it.

 

[AARONTLC]

Chasing a P0430 CEL code (Catalyst system efficiency below threshold bank 2) popping up every few hundred miles on my 2005 Land Cruiser. I’ve tried a bottle of CATACLEAN that didn’t seem to do much.

I’ve search threads and seen folks suggest a myriad of solutions. My question is, have any of them ACTUALLY worked? Those who have had P0430 (or P0420), what did you do that finally fixed it?

Anyone had success with new MAF sensor replacement? O2 sensor replacement? Miracle in a bottle? “Italian Tune-up”?

Appreciate it.

View attachment 4040968

You will probably get a bunch of "Yes" and "No" answers to all of the above components being replaced. The 0420/0430 codes are a drag because they can be so expensive to fix. I would start with checking your O2 sensors per the FSM and cleaning your MAF with proper cleaning spray if you suspect them. Do you have any exhaust leaks at the exhaust manifold? (Ticking sound when cold?).

IMO the CAT's on the 100 series are very easy to remove so trying a "snake oil" solution is worth a shot if everything upstream checks out as good. There are several videos and threads on cleaning the CAT. Buy $20 worth of OEM replacement bolts and exhaust gaskets and try cleaning it.

 

[GremlinMobile]

I have the same issue. P0420 and P0430 codes. I also have a GX470 that has a MUCH louder exhaust tick with an obvious cracked exhaust manifold that I've already repaired once. However, I have no P0420 or P0430 codes. So an air leak doesn't seem to be what would cause that...

I'm also trying to figure this out and am afraid of going through the work of taking both CATs off and shearing bolts and getting way in over my head. Then my car will be stuck in the driveway for days

 

[BullElk]

On my '06LX, I have used the spark plug nonfouler contraption with pretty dog gone good success. I have to clear the codes maybe 3-4 times per year. YouTube videos on how to install.

 

[scubadoober]

The root cause for both of these codes is either running rich for a long time, or oil in the combustion chamber. With that said there is no silver bullet, and the cat might be actually too far gone. Your only real solution is the CAT cleaning method with lye and acid to try and clean the residue and bring it back to some sort of working order.

 

[GremlinMobile]

It seems that those non-OEM non-california CATs are not crazy expensive. If I'm going to unbolt the cats and risk messing around with rusty nuts and bolts, to try to mess around with DIY cat cleaning methods which may or may not work in the long run, why not just get a new $300 converter from rockauto?

 

[OEMGUY0720]

Replace/service the following:
•MAF sensor.
•Intake and vacuum hoses for leaks.
•Fuel pump and all fuel delivery associated components.
•Coil plugs.
•Spark plugs.
If you have pre-vvti 2UZ, you have better chances of getting the P0430 error resolved with the above mentioned approach.
If your 100 is VVTi 2UZ, it is likely your catalytic converter on top of all the items I mentioned above.
This is speaking from personal experience.

 

[white_lx]

First thing to do would be to ensure there are no exhaust leaks. Put a shop vac in blower mode and connect it to the tailpipe. Listen and feel for any leaks.

The next step is to determine the state of the catalytic converters using an oxygen storage test. Using a bi-directional scan tool, drive the exhaust rich (O2 sensors go high). The primary B1S1 and B2S1 sensors will immediately show a rich condition. The secondary sensors B2S1 and B2S2 will be delayed due to the oxygen stored in the catalytic converters. The longer the catalytic converters can store oxygen, the better the catalytic converters are. If you get less than 1 or 2 s delay, your catalytic converters are on the way out and there is no point in changing anything else, besides possibly trying sensor spacers/fowlers on the secondary sensors.

Below is an example of a set of good functioning catalytic converters. Yellow and red curves (primary) go fuel rich first, followed by green/blue (secondary sensors) with a delay of approximately 5 seconds. The flag markers in the top of the graph show where the engine is driven rich and lean with the scan tool, in this case Techstream.

If you are only getting a P0430 code, you can verify the oxygen storage capacity between your L&R bank to see if the P0430 is actually caused by a worn catalytic converter. In the example below the L&R banks behave near identical.

 

[willmtaylor]

Thank you all. Gonna start digging on the easy stuff myself now. Appreciate all the input, sincerely.

 

[2001LC]

We must look for why PO430 or 20 DTC is happening. Or we'll likely repeat. Is CAT damaged, clogged or are we getting false DTC:

1. Prolonged idling. OM warns against.
2. Engine in need of a tune up. Vacuum leaks, fuel inject issue, fuel pressure issues, bad spark plugs, weak coil.
3. Bad MAF sensor, will take out a CAT fast. Mostly will result in very rich fuel air mixture. Raw fuel ignites in CAT, burning it up. A bore scope run into A/F or O2 port can be easy revealing.
4. Damaged cylinder, to point of failing compression test.
5. Oil in combustion camber. Bad valve steam seal or rings. Excessive oil, can also ignite in CAT.
6. Exhaust leak. I've not seen this happen, and have seen very bad long term leaks from cracked exh man. I have seen A/F or O2 seals leak, result in CAT out of threshold DTC. ECM, can get false reading from O2 or A/F, resulting in rich mixtures. But yet A/F or O2 is okay.
7. Coolant leak into heads. Coolant will damage CATS. Borescope and oil analysis are best tools. Excessive cold start white smoke with sweet smell is clue.
8. Impact to CAT, busting CAT material.
9. Clog up CAT. This is where CAT cleaners may help.

• Logging fuel trim periodically, is good idea! Whenever we see them out of range, we need to investigate why.

O2 extender. Fool the system. They do not correct cause. You may, damage the engine, if cause not corrected.

 

[unatiq]

Does anyone know which O2 sensor to buy to trick the truck into thinking the cats are functioning good? I had aftermarket cat installed and it lasted for a year or so. I’m at the point where i would rather go the cheap route and install spacers to trick the system.

Please share any links you have.

 

[OEMGUY0720]

Does anyone know which O2 sensor to buy to trick the truck into thinking the cats are functioning good? I had aftermarket cat installed and it lasted for a year or so. I’m at the point where i would rather go the cheap route and install spacers to trick the system.

Please share any links you have.

Any brand will do as long as you got the correct tread pitch. Caveat on the O2 sensors, especially if you have the VVTi 2UZ is to check your spark plugs at least every 15k miles. Since one of the 2 banks of the engine will be compensating spark because of the different readings the O2 sensors will get, eventually you will see premature wear spark plug tip wear, just a heads up. But other than that, it should work as intended.