P0420 and P0430 - 2006 LC (3 Viewers)

[jerryb]

if a toyota mechanic looked at that he'd say you're fine. -+35 will get you a code, vvti.
IT's better if you watch wideband and narrow band o2 sensor voltage, considering you have a 420. It still could be a random occurrence. If it happens repeatedly then it's probably real.
Watching all four voltages, then you'll have info to swap sides (if you can) see a dead one. See a stagnant one reading hi/lo etc

 

[white_lx]

I keep getting a P0420. I clear the code and it returns the same day. Attached is some info i pulled my my cheap code reader. Something looks off. Anybody want to translate that into layman's terms for me?

Long term fuel trims are a bit high - but nothing too crazy. Photo shows +7% trims at ~1500 rpm. How are the numbers at idle and at 3000 rpm? Do they get better with higher RPM? Then you have a vacuum leak. If they get worse then it probably is a dirty MAF (or maybe even a dirty air cleaner filter).

The picture you shared does not have enough information to diagnose the P0420. For that you need to monitor the four oxygen sensors as per post #361.

 

[Baumer06]

2006 LC100 here with 271K miles on it. Just went through a Secondary Air Injection headache. Got that fixed and now I’m throwing a P0420 & P0430 code. I’ve changed the air filter, PVC, and both O2 sensors with no luck.

I’d second the request for additional information on the URD 4.7 O2 bi-pass. Any information on the correct model to get for the LC100, where it clips into the O2 sensor harness, and configuration/settings would be extremely appreciated.

 

[jerryb]

Can be located second page on the 100 forum right now. Edit, 3rd page

here.

 

[2001LC]

2006 LC100 here with 271K miles on it. Just went through a Secondary Air Injection headache. Got that fixed and now I’m throwing a P0420 & P0430 code. I’ve changed the air filter, PVC, and both O2 sensors with no luck.

I’d second the request for additional information on the URD 4.7 O2 bi-pass. Any information on the correct model to get for the LC100, where it clips into the O2 sensor harness, and configuration/settings would be extremely appreciated.

What A.I. codes did you have, prompting you to fix Secondary Air Injection? What was done?

It's possible, your 2ndary switch A.I. issues is related. I'll be exploring this possibly soon.

 

[farright]

Magnaflow is supposed to be coming out with direct replacements for the 2006 and 2007 100 series fairly soon from what i read...

 

[looking4lc]

What A.I. codes did you have, prompting you to fix Secondary Air Injection? What was done?

It's possible, your 2ndary switch A.I. issues is related. I'll be exploring this possibly soon.

any update?

 

[2001LC]

No. I'll not have time to work on my stuff until this winter. Words gotten around, that I work on 100 series. So list of locals' rigs keeping me too busy.

If anyone with this issue past or present. Has all code (DTC) pending or active, that were found with or about same time as P0420 & P0430, could list them?
That would be helpful.

 

[2001LC]

For those that have read this far and missed the edit in post #2.

I did come up with what IMHO. Is the leaning cause of the 100 series 06-07 4.7L 2UZ-fe VVT CAT P0420 & P0430 failures.

IMHO they will all fail, if not modified.

I've came up with a theory, of what's damaging the CATs. Worked to prove out. Then a solution!

I tested this on a 2007 w/reoccurring P0430 & P0420. It's been more than 2 years since I modified this 07, with a perfectly street legal modification. It has work perfectly. IMHO all Toyota/Lexus with the Secondary Air Injection (S.A.I.) system, which was introduced in most after 2005, to meet environmental laws. Will fail if not dealt with.

You can read about it and how to modify to correct, in the below thread.

S.A.I. Modification in VVT engines to prevent its failure! Alert Alert

We've a $2.00 part in the S.A.I.S. of the VVT engine, 1s taking-out ~$7,000.00 $15,000 (inflation) in parts. WOW! I've a very easy and cheap WORK AROUND. You are going to love this ;) This thread is dedicated to the 4.7L 2UZ-fe VVT engine, in the 2006 & 2007 100 series Land Cruiser & Lexus...

forum.ih8mud.com

 

[jerryb]

You're that bored?

 

[planomateo]

You're that bored?

I appreciate his persistence on this.

 

[2001LC]

You're that bored?

Nope. Just saw that I'd not updated since 2020, when asked.

So update: Found cause, came up with solution, tested and works without issue. No more P0430 or P0420 or S.A.I. DTC, and street legal.