Annoying P0430 need to solve it. (2 Viewers)

[looking4lc]

Hey mudder.

My lx has 345k now and all maintenance is up to date except this p0430 is keeping popping every two weeks or so. I am 80% sure is not the o2 sensors because I replaced them 2 years ago , denso (when I had same code and disappeared for like a year) nor it’s the cat converter. This issue is bugging me and I want it fixed.
Note:1- I have small coolant leak somewhere and couldn’t find it yet I checked everything and didn’t find any sign of leaks. possible from lower Radiator hoses which I didn’t check yet.

2- ticking sound ( not sure how to describe it) but if I start the car and go to front wheels well, I hear ticking from both sides maybe one is louder than the other. I asked few friends and they were sure it’s a exhaust leak, however, it’s not loud when start it in the morning.

Since I haven’t done major maintenance besides, TB and cam seals, am thinking to do the following as PM and could solve the code issue and want your recommendations

1- check exhaust manifold and replacing gasket for both sides , if there is any ( I think that’s where the ticking from) also might be a air leak and trigger the code.

2- replace manifold intake gasket for PM. Since never been done.

*******Don’t want to replace Cat****

Your insight is really appreciated

 

[looking4lc]

Random pics. Maybe you see something I don’t. And the yellow circle is broken bolt

 

[2001LC]

Causes of P0430: Bk 2 CAT readings out of threshold.

1. CAT's go bad if damaged from a hard hit, breaking up the ceramic honey cone materiel in them. Some say a rapid temperature change can fractures the CAT. Like driving in cold water when CAT very hot. CAT manufactures say, water just evaporates off case.
2. Raw fuel in CAT form running to rich. CAT cooks itself (excessive internal heat), falling apart from within.
3. Clogged CAT from containment get in them. Oil from bad engine cylinder rings is one way. Carbon build up from poor running engine can be another. Drive at low RPM never getting to HWY speed/higher RPM for longer periods with poor running engine can clog them. CAT basically are self cleaning like an oven. At higher RPMs when internal temperature at effective CAT threshold, they cook off normal contaminants that could clog them. That said the 4.7L 2UZ is well suited for low speed driving.
4. Coolant leak. It said the coolant renders the CAT useless.
5. Exhaust leak pre CAT. Additional oxygen result in excessive heat in CAT. This heat may damage CAT. It also may confuse A/F and O2 sensor. This in-turn may cause fuel trims to too run rich, as ECU reads this as running lean (hot) and correct increasing fuel in mix (cool).

You've said two things I find potential causes of a BAD CAT or inaccurate reads by O2.

1. Tick. Exhaust leak that is present during normal operation temp can damage CAT and or give inaccurate reads by O2.
2. Coolant leak not identified. If you've a head gasket leak of coolant into any of bank 2 cylinders (2,4,6,8) it will damage the CAT.

Additionally you've replaced O2. A leak at it's cruse washer, O2 walked out, Os' prob touched, defective O2.

I'd swap O2's and clear codes, see if codes moves or returns. A note O2 has a crush washer. Crush washer do not work well a second crush (torque in of O2). I Use AC Delco G18mm O2 crush washer and replace them.

I'd work to detriment:

1. If and exhaust leak!
2. If a head gasket leak.
3. Make sure engine running at peak performance.

CAT do not just "normally" go bad. They're affected be some thing upstream. If not corrected they will go bad again after replacement.

I' just had a case where a CAT was improperly installed by INDY Midas Shop tech. It had 3 apparent micro air leaks between engine and rear O2. Additionally the O2's threads had a gray threads seal goop on them. The Tech was sloppy getting the gray goop on ~20% of the O2's prob. The prob portion of the O2 should not even be touch with one's fingers. Any contaminated on them can cause them to go bad. In this case the gray goop was interfering with prob getting accurate readings.

RT help. I've new exhaust nuts stuck. Any ideas?

One good thing. I may have found my P0430 cause!

forum.ih8mud.com

 

[blatant]

I may be late to the show, but a new gas cap fixed my p0430code 10k miles ago.

Also, what's that shiit wrapped and zip tied?

 

[BamaHeel]

Has anyone tried using a spacer like this:

M18 X 1.5 Metal O2 Oxygen Sensor Adapter CEL eliminator With Catalytic Converter | eBay

I've heard that cats can go bad overtime and this seems like a simple solution.

 

[looking4lc]

Causes of P0430: Bk 2 CAT readings out of threshold.

1. CAT's go bad if damaged from a hard hit, breaking up the ceramic honey cone materiel in them. Some say a rapid temperature change can fractures the CAT. Like driving in cold water when CAT very hot. CAT manufactures say, water just evaporates off case.
2. Raw fuel in CAT form running to rich. CAT cooks itself (excessive internal heat), falling apart from within.
3. Clogged CAT from containment get in them. Oil from bad engine cylinder rings is one way. Carbon build up from poor running engine can be another. Drive at low RPM never getting to HWY speed/higher RPM for longer periods with poor running engine can clog them. CAT basically are self cleaning like an oven. At higher RPMs when internal temperature at effective CAT threshold, they cook off normal contaminants that could clog them. That said the 4.7L 2UZ is well suited for low speed driving.
4. Coolant leak. It said the coolant renders the CAT useless.
5. Exhaust leak pre CAT. Additional oxygen result in excessive heat in CAT. This heat may damage CAT. It also may confuse A/F and O2 sensor. This in-turn may cause fuel trims to too run rich, as ECU reads this as running lean (hot) and correct increasing fuel in mix (cool).

You've said two things I find potential causes of a BAD CAT or inaccurate reads by O2.

1. Tick. Exhaust leak that is present during normal operation temp can damage CAT and or give inaccurate reads by O2.
2. Coolant leak not identified. If you've a head gasket leak of coolant into any of bank 2 cylinders (2,4,6,8) it will damage the CAT.

Additionally you've replaced O2. A leak at it's cruse washer, O2 walked out, Os' prob touched, defective O2.

I'd swap O2's and clear codes, see if codes moves or returns. A note O2 has a crush washer. Crush washer do not work well a second crush (torque in of O2). I Use AC Delco G18mm O2 crush washer and replace them.

I'd work to detriment:

1. If and exhaust leak!
2. If a head gasket leak.
3. Make sure engine running at peak performance.

CAT do not just "normally" go bad. They're affected be some thing upstream. If not corrected they will go bad again after replacement.

I' just had a case where a CAT was improperly installed by INDY Midas Shop tech. It had 3 apparent micro air leaks between engine and rear O2. Additionally the O2's threads had a gray threads seal goop on them. The Tech was sloppy getting the gray goop on ~20% of the O2's prob. The prob portion of the O2 should not even be touch with one's fingers. Any contaminated on them can cause them to go bad. In this case the gray goop was interfering with prob getting accurate readings.

RT help. I've new exhaust nuts stuck. Any ideas?

One good thing. I may have found my P0430 cause!

forum.ih8mud.com

Thanks Paul

1,2, and 3 eliminated since no damage nor i drive slow/low RPM. i drive 500 Miles a week with 85MPR. so no issues there.
possibility for 4 and 5 since i have done my reading and those what i conclude where the issue is.

Head gasket, i will check that but i doubt it cause i change the oil (myself) every month and i dont see any up normality there.
switching o2 is good idea, will start with that. but i didnt understand the part with the washer!!!!! explain please.
and exhaust leak will doi some smoke testing or so to see if there is any.

appreciate it

 

[looking4lc]

I may be late to the show, but a new gas cap fixed my p0430code 10k miles ago.

Also, what's that shiit wrapped and zip tied?

Gas Cap??? Interesting (oh it would be cheap fix)
the wrapped is AC pipe, heard would make the AC ice cold in the summer but it didnt, will remove it

 

[looking4lc]

Has anyone tried using a spacer like this:

M18 X 1.5 Metal O2 Oxygen Sensor Adapter CEL eliminator With Catalytic Converter | eBay

I've heard that cats can go bad overtime and this seems like a simple solution.

ya i know about this but that will just make the light goes off, i want to fix the root of the issue.

 

[2001LC]

When you swap O2's (rear sensor) or A/F (front air fuel sensor in the VVT engine) the crush washer (which is a gasket) on them will have been used (crushed). They don't seal as well a second time (re used)

This is a used O2 sensor (rear) from a USA 4.7L VVT engine. It's crush washer, has been crushed at least twice now.

I clipped off old washer and replaced with new 18mm crush washer. One of these from AC Delco G18mm O2 crush washers.

I also filed flat the point on CAT, where the washer seals/seats O2 to CAT. But I had CAT off, so I could file with port of O2 facing down. That way, no metal fillings would get in the CAT. I then torque the O2 with new crush washer to 32ft-lbf.

Notes:

1. I would not have used a file on port that O2 threads into CAT, while CAT on the vehicle. As I would not want, any metal filings getting into CAT.

Any air leak at threads of O2 or A/F sensor can increase temperature around the probe. This can give a false P0430 or P0420.

This one, a tech at INDY Midas shop had many leaks, do to improper procedure (he was and idiot). One at exhaust pipe gasket flange to CAT pipe flange. Another one at threads of a extra O2 hole for an aftermarket CAT. The extra hole in this case, is just to be plugged, as I showed in the thread I linked you to above.

The Tech also use a gray goop (thread sealer or lube IDK). In doing so, he was sloppy and got some gray goop on the probe of O2. Very bad idea. You only see a little of the gray goop, there was more.

 

[2001LC]

Did you also have a P0420 before replacing O2's?

Did you replace O2's (rear, or down stream) or A/F (forward, or upstream in VVTi engine) or both?

In your case, it is the loose of coolant I find most interesting. I'm not saying your up stream issue is a head gasket or cracked block. But we should never need to add coolant in a properly maintained and working coolant system. You need to find leak first thing.

A compression test will be useful. But you'll need more testing also.

1. Compression test.
2. Leak down test.
3. A long term pressure test of coolant system (24 hours)
4. A head gasket leak may seal itself once engine at operating temp. Than leak some small amount of coolant into a cylinder, once cold engine or during cooled down. Then you start up, and a small amount may get pushed into CAT. Cold CAT, coolant would just disperse inside honey comb of CAT.
5. Inspecting ever inch of the outside head gasket may also be reveling. But a leak can just be internal. On the VVT engine we can not see the head gasket under intake, with a scope.

I just grab this Video off a google search.

 

[blatant]

the gas cap gasket gets aged and becomes rock hard, no longer soft/sealing, allowing an air leak.

 

[wsudu]

I think that was the code that I threw last year which pointed me to bad O2 sensors. I replaced with Denso but not OEM Denso. Well it came back on and I found our that it was actually the A/F sensors going bad sending the O2 sensors off. I just replaced all 4 as PM, no problems now.

 

[2001LC]

OP may just have a small issue. Maybe just defective O2 or has a Wonky A/F, etc.... We can hope!

Many things upstream stream can affect the CATs. Wonky A/F's & O2's certainly can give a bad reading. Gas cap, fuel pressure, fuel injectors, MAF, Vacuum leaks. Those pre head or exhaust issue that may result in both P0420 & P0430 at or about the same time. Most of those should give their own DTC, but sometimes just don't! Why! I suspected they just aren't quite out of spec. Those "near out of spec" issues can add up.

With just a P0430 or a P0420 only, we focus more on that bank. P0430 is bk 2, so we focused more on head to rear of O2 in bk 2. Like bk 2 Vacuum leak (intake gasket of Bk 2), fuel injectors & seals, spark plugs, coils, valves, head gasket, exhaust leaks.

In OP's case, he's mention coolant loss. It's very import to identify this before proceeding. Not only could this damage CAT, but the engine. The concerning statements is he "didn't find". Every coolant leak I've seen, can be found externally on engine with time. Some, like at head gasket that "are" external can be very hard to see. I inspect each side of engine with flash light and a mirror. I do this with all lower and upper covers off. In the VVT engine seeing head gasket under intake manifold is not possible, without a camera. I use a $40 drain snake camera hooked/Wifi to my iphone. Only one I can think of, that can't be seen, would be into a cylinder. I'm not saying this is PO issues. But must be determined as a first step.

Second issue PO stated, was ticking after warm up. This may just be the fuel injectors ticking. But if and exhaust leak needs identified and repaired.

Also unless one has a virgin 100 series, never touch by anyone's hands. We've may have old procedure repair errors (mess ups) to contended with also.

Getting all in proper working order first, is key to P0420 or P0430 not coming back.

I've heard some say you can tell if a CAT bad, by thumbing on it with a rubber mallet. If something rattle bouncing around in it, it's bad. Well, yes I suppose if CAT fell apart. How would it fall apart. Impact for one. It can also burn up from within and fall apart from raw fuel dump in CAT. But that rich a fuel condition and cylinder temp runs cool. Maybe one or two fuel injector pump in excessive fuel could do this. Sensor read as rich and leans fuel trim of that bank. Yet that or those bad fuel injects just keep dumping excessive fuel. Also excessive leak down of fuel injectors. Then we start and dump raw fuel in cylinder could also be issues, I suppose. Excessive leak down is generally associated with long crank time to start engine. This condition and others related to fuel injectors are more seen with low mile engine. Engines that sat long period of time without be started or used bad fuels with water. Watching fuel trims can be useful tool. There is also a way to shut down a fuel injector with Toyota Tech steam SST tool. Unfortunately we can't do (that I've seen) with a $20 miny VCI hook up to tech stream.

 

[looking4lc]

Did you also have a P0420 before replacing O2's?

Did you replace O2's (rear, or down stream) or A/F (forward, or upstream in VVTi engine) or both?

In your case, it is the lose of coolant I find most interesting. I'm not saying your up stream issue is a head gasket or cracked block. But we should never need to add coolant in a properly maintained and working coolant system. You need to find leak first thing.

A compression test will be useful. But you'll need more testing also.

1. Compression test.
2. Leak down test.
3. A long term pressure test of coolant system (24 hours)
4. A head gasket leak may seal itself once engine at operating temp. Than leak some small amount of coolant into a cylinder, once cold engine or during cooled down. Then you start up, and a small amount may get pushed into CAT. Cold CAT, coolant would just disperse inside honey comb of CAT.
5. Inspecting ever inch of the outside head gasket may also be reveling. But a leak can just be internal. On the VVT engine we can not see the head gasket under intake, with a scope.

I just grab this Video off a google search.

Thanks paul for the info,
Yes I believe I had both 0430 and 0420 before and I only replaced the o2 not the AFs.
I will be checking the exhaust leak, replace gas cap too.
will you be able to ready the o2 sensors and AFs if I post some values here or screenshot?

 

[2001LC]

I can try to read the data, but not my strong suite!

I'm going to send you a PM. I found something I am still reaching that I do not want to disclose in the forum yet.

 

[LongHaulCruiser]

Lot of partially burned fuel will make the cat work hardest, and may not be working at proper level. Driving so fast will make lots of work for the cat. I would make sure the engine was tuned really well and take it a bit easier when driving it.

 

[looking4lc]

Lot of partially burned fuel will make the cat work hardest, and may not be working at proper level. Driving so fast will make lots of work for the cat. I would make sure the engine was tuned really well and take it a bit easier when driving it.

up to date maintenance all around it, not every time i drive 85mph, but somewhere close. i was trying to say to previous post that the truck has not been driving like old man

 

[2001LC]

I take my 100 series 4.7L 2UZ out on HWY and run them very hard intentionally. Some call this an "Italian tune-up", "carbon cook-off" or "burn out"

If raw fuel is dumping in CAT(s). Then yes, CAT can burns up at these high temps. But I've not seen or heard of this happening on a 4.7L 2UZ .

What I have seen is CAT clogged and no amount of cook-off or additive un-clog them.
View from up stream looking at face of front of a clogged CAT.

Looking up stream from back of front CAT ceramic honey comb material (same CAT as above).

I'll do during Italian tune-up before, during and after adding cleaning products such as 44K, sea foam fogger, Cat-Clean. etc.

I'll drop transmission down to 3rd even second gear, depending on speed. I shoot for greater than 4.5K RPM or 5K RPM in VVT engine. This is like driving around 130 MPH in 5 spd trans model. I'll do this for 5 to 10 minutes rest by driving in D than repat, and have done as long as 30 minutes. This runs temp in CAT up, which is good for the CAT. Cleans them like turning your oven to self-clean. Provided engine fuel/air mixture in line. If raw fuel dumping in CAT. Fuel burning within CAT honeycomb can burn up ceramic material (or so I've read)

The greats risk using these cleaning products. Is if engine fuel and air system have to much gunk and or cylinder heads too much carbon build up. They can dump to much to fast into CAT and clog them.

Making sure engine well tuned (good oil & filter, air filter, PCV good working order, spark plugs, no vacuum leaks, etc.) and doing Italian-tune before adding any cleaner products, helps reduce risk of slugging/clogging a CAT.

 

[OEMGUY0720]

My experience in P0430 on my 06 5-spd VVTi (all possible relation to solving this problem):

- replaced both L&R O2 sensors @ cat with original Denso (not from toyota/lexus) - still has P0430
- replaced both L&R O2 sensors @ exhaust manifold using OEM bought at Lexus dealership $$$ - still has P0430
- replaced fuel bnew filter - still has P0430
- serviced (pulled down the whole intake manifold, cleaned/decarbonized the ports and valves, intake manifold, MAF sensor - still has P0430
- replaced all 8 injector gasket o-rings with bnew OEM ones - still has P0430
- replaced bnew Denso fuel pump - still has P0430
- replaced all old spark plugs with iridums 8ps - still has P0430
- did Paul’s @2001LC suggested italian tune-up - still P0430
- replaced old air filter with bnew OEM air filter - still has P0430


Pretty much performed all possible things related to addressing P0430 but to no avail. The last step is to replace the catalytic converter assembly itself, but I haven’t yet done that Lol. I just keep resetting it using my DTC scanner.

 

[2001LC]

IIRC:

You had stall issue at high OAT last summer. That replacing fuel pump corrected.
You also found some signs of intake vacuum leak.

I've been studying this issue in the VVT. The CAT pictured above was clogged, nothing cleared/clean it that I tried. Even after other issues corrected DTC remained. DTC are now gone, as CAT's replaced. Clogged CATs is always up stream issues, unless maybe deep water washed something in tail pipe. All up stream issue must be corrected before CAT replaced, or it comes back. Which You likely done with all your work.

Here's what I'm trying to warp my head around. Why is a weak fuel pump which seems associated with many of these VVT getting a P0420 & P0430 possible causing these CAT to clog.

I'm trying to collect any CAT anyone removes, to see if clogged or damaged in anyway.

In case I'm now working on, a P0430 returned after CAT replaced. It turns out the Midas shop tech really made a mess of it. I've correct his mess and no P0430 and I also replaced the other CAT and no P0420. But I'm concerned that P0430 may come back. This tech not only got gray goop the prob of O2, he likely touched it. So O2 may go bad or just not read/work well enough. That Midas tech also created many air leaks pre O2 and next to O2.

Exhaust Air leak up stream of CAT can damage them also. But I scoped all 4 ends, and this one which was replaced 4K miles ago looks Okay. Except for a little gray goop on down stream of rear CAT face. I don't see this as issue.

Looking upstream CAT face, looks very good