2004 Lexus LX470 270k P0430 code

[whereditgo]

Getting a P0430 Bank 2 Sensor 2 CAT efficiency code.

Ready to install new after CAT O2 sensors, RA Denso on hand.

Running a few tanks of Super and possibly some CAT cleaner/lacquer thinner to clean out the CATs and hopefully not cause other issues.

Prior to those measures thought I would post some engine data for crowd diagnostics. Can run different test data if needed. Cold/hot/load variations.

Hoping to avoid the CAT replacement $$$.

Thanks in Advance?

 

[whereditgo]

Torque Lite Screen Capture here;

 

[OEMGUY0720]

You have a better chance of getting your P0430 fixed by replacing your your upstream and downstream O2 sensors than us with VVTi. Also, check your spark plugs and coil plugs as well as your MAF sensor make sure they are good.

 

[menancyandsam]

see this thread...https://forum.ih8mud.com/threads/p0430-2003-landcruiser-solved.1337102/

Cleaning the cat worked for me & a few others.

 

[whereditgo]

Appreciate the spark plug/coil advice. Those were replaced when I did timing belt 70k miles ago with NGK Iridium's. Thought plugs would be ok, but upon inspection all electrodes on bank 2 (2,4,6,8) were dusted and bank 1 (1,3,5,7) were worn. Replaced with IK20TT's. Power and response significantly improved. Will see if any codes come back...

 

[whereditgo]

Cleaned MAF as well.

 

[miroza]

Check the exhaust pipe for leaks, including the lambda probe seals. Any holes in the pipes or fittings.

 

[whereditgo]

Check the exhaust pipe for leaks, including the lambda probe seals. Any holes in the pipes or fittings.

Did not see any obvious leaks between engine and downstream O2's

Difficult to inspect around manifolds with heat shields in place. Plan to back feed shop vac in tailpipe and spay with soapy water to see if any tell tail bubbles appear.

Know getting both P0420 & P0430 codes within a couple drive cycles. Another downside is truck is primarily driven on short local trips (not great for the cats). Fuel mileage pretty bad 10.8 MPG on trip info.

After lots of research and minor parts cannon, I am suspecting leaking exhaust manifolds TIK..TIK..TIK.

Understand it is very important to resolve the issue of what is clogging the cats before cleaning/replacing them.

So far...

Have a working Toyota Techstream for further diagnosis. Reports error both rear (downstream) O2 with P0420/p0430 max value 0.499/ fail 0.812. Think this is a ratio of fail/good Cat tests based on Toyotas diagnosis tests....

New rear downstream 02 with gaskets (genuine Toyota)..
Cleaned MAF, new (genuine Toyota( on the way.
New Denso Spark Plugs (Rockauto)
New Air Filter
Smoke tested Intake and checked puge valves (no leaks and valves are functioning correctly).

I am ready to soak the cats in a warm bath of citric/oxalic acid and distilled water and possible electric hot water pump to circulate.

Have supplies and new gaskets for cat clean and replace and acquired an old brew master beer keg.

Attached are links to a video of bank1/bank2 exhaust manifolds on cold start. Ticking sounds louder on video then in person.

Also pic of rear O2's that were replaced. They actually look fairly clean/minimal carbon build up.

(Yup, need to replace leaking valve/rocker cover gaskets...)