P0420 and P0430 - 2006 LC (37 Viewers)

[white_lx]

To rule out catalytic converter damage you can do an oxygen storage test. The post cat oxygen sensor goes lean later because a good cat will store oxygen. Found this example (for a Toyota V8 with 200k-km):

 

[OEMGUY0720]

Edit:

@2001LC So far the “stalling during hot day temps” hasn’t occurred yet. I will be updating as soon as I drive out on a hot afternoon on the same conditions when it happened the last time 108°F and up.

Here’s the side by side comparison of the two fuel pumps:

The photo of the used plug in post #290 shows 'JAPAN'. Are those the original plugs at 235k miles?

I have no idea if those spark plugs are still original or has been replaced before. No records referring to a spark plug replacement. I got the truck at 233k miles. Picked this truck from Houston TX and drove to Las Vegas NV w/o any problems.

 

[OEMGUY0720]

To rule out catalytic converter damage you can do an oxygen storage test. The post cat oxygen sensor goes lean later because a good cat will store oxygen. Found this example (for a Toyota V8 with 200k-km):

Is this Techstream that the guy is using on the video?

Edit: finally browsed the functions of Techstream and found this so I went ahead and saw how the values change when I manually adjust -12.5 or 0 or +12.5.

 

[OEMGUY0720]

@2001LC I once again did a back read last night and saw you pulled down your intake manifold given the truck has no CEL. I inspected my truck more last night and discovered I “may” have a leak (possibly OIL and/or COOLANT) on the intake manifold area. So I have decided to take a look at it and will start the removal today.

I am now preparing parts for this like gaskets, seals, crush washers to be replaced. Like others have mentioned on this thread, I’d like to get to the bottom why CATS fail. Because even if I replace the CAT, without getting to the bottom of the problem, I’m actually not solving it, I’m just doing a band-aid short term solution. So the best thing to really do is address the root cause.

So in light with this, I may need help in the parts number area. Need part numbers for:
• intake manifold gasket (orange color) - I think I need two of these? For both driver side and passenger side
• injectors crush washer part numbers - I need 8pcs of these for all 8 injectors?
• water bypass gasket - I need 4 of these? (two for the front and two for back)
• O-rings?

What else do I need? Thanks in Advance.

 

[2001LC]

Id like to see you hold off on intake gaskets, until you've have repeatedly "test driven" where you're at now.

You did a very good job getting engine tuned (back to spec), ruling out much of what could be factors. I'm very hopeful your hot day test will go well. This would point so heavenly to fuel pump.

I'd also suggest finding a mountain ascend and descend in one pass. I found I could repeat my stalling in my current test subject, this way (just as OP did). Stalling just after letting off gas peddle as I crested the passes. I'll be starting with making sure engine is inline i.e. plugs, coil, vacuum, filters, etc, okay. But avoid doing to much more at first. I'll first install OEM gas cap, then test drive. Then due a fuel pump replacement and test drive. My case may be different of course. But could be the same root cause, but has just been going on longer. I say this as I've CAT DTC and the CAT was replace. It will be tough call for me on CAT, as it's replacement was not OEM. It's that slipper slope.

I've vary thoughts on fuel filter. Sure one can get bad gas and clog it. Some in mud have cut open, and they're sure element is so dirty it slowed flow. But Toyota seem to think they're a life time filter. Doing your driving test before filter replacement will be valuable data.

The stall issue is one thing. But I'm also thinking that low fuel pressure may be cause and effect for CAT DTC issue. Whereas replacing CAT does not solve issue and code come back. My thinking is lean condition is cause engine cylinder head to run hot. A/F and O2 readings have ECM constantly adjusting fuel trims trying to keep up. That over time these systems mostly A/F sensor (front O2) weakens and will give off a DTC. It seems more prevent at high altitude. Why could have to do with atmospheric pressure drop.

Keep in mind the intake manifold, gasket and heads expand when hot. This likely seals any leak in most. Where I once may have thought this a leading factory, I'd now say secondary. That currently my thinking has shifted to fuel pump as primary.

The intake manifold gaskets and throttle body gasket is all you need. Anything else like fuel injector (FI) insulators (between FI & manifold) or fuel rail washer/gaskets are only needed when pulling injectors. Some for Water bypass joints I'd just do if leaking.

17171-50030 x 2 intake to head gaskets
22271-50050 throttle body to intake

Make sure to verify PN # with your VIN #.

 

[OEMGUY0720]

Id like to see you hold off on intake gaskets, until you've have repeatedly "test driven" where you're at now.

You did a very good job getting engine tuned (back to spec), ruling out much of what could be factors. I'm very hopeful your hot day test will go well. This would point so heavenly to fuel pump.

I'd also suggest finding a mountain ascend and descend in one pass. I found I could repeat my stalling in my current test subject, this way (just as OP did). Stalling just after letting off gas peddle as I crested the passes. I'll be starting with making sure engine is inline i.e. plugs, coil, vacuum, filters, etc, okay. But avoid doing to much more at first. I'll first install OEM gas cap, then test drive. Then due a fuel pump replacement and test drive. My case may be different of course. But could be the same root cause, but has just been going on longer. I say this as I've CAT DTC and the CAT was replace. It will be tough call for me on CAT, as it's replacement was not OEM. It's that slipper slope.

I've vary thoughts on fuel filter. Sure one can get bad gas and clog it. Some in mud have cut open, and they're sure element is so dirty it slowed flow. But Toyota seem to think they're a life time filter. Doing your driving test before filter replacement will be valuable data.

The stall issue is one thing. But I'm also thinking that low fuel pressure may be cause and effect for CAT DTC issue. Whereas replacing CAT does not solve issue and code come back. My thinking is lean condition is cause engine cylinder head to run hot. A/F and O2 readings have ECM constantly adjusting fuel trims trying to keep up. That over time these systems mostly A/F sensor (front O2) weakens and will give off a DTC. It seems more prevent at high altitude. Why could have to do with atmospheric pressure drop.

Keep in mind the intake manifold, gasket and heads expand when hot. This likely seals any leak in most. Where I once may have thought this a leading factory, I'd now say secondary. That currently my thinking has shifted to fuel pump as primary.

The intake manifold gaskets and throttle body gasket is all you need. Anything else like fuel injector (FI) insulators (between FI & manifold) or fuel rail washer/gaskets are only needed when pulling injectors. Some for Water bypass joints I'd just do if leaking.

17171-50030 x 2 intake to head gaskets
22271-50050 throttle body to intake

Make sure to verify PN # with your VIN #.

Thanks for this. The past few days I’ve been driving it like I stole it, revving it hard to accelerate in hopes (knock on wood not) recreate my initial symptoms of stuttering during take off and eventually stalling (this was my first issue before P0430) when idled long under the heat of the Vegas sun at 106°F, but to no avail, no more of that engine dying because of heat soak, problem solved. I have yet to try what you’re recommending to drive in a mountain pass or higher altitude place, nearest one where I live is Mt. Charleston, will report back soon when we visit the place.

But, P0430 is still here, and I also believe that even if I replace the CAT (leaning to an aftermarket cat to save $$$), it may or may not solve the P0430 and eventually down the road will do leak fix and then risking other parts to get compromised because I delayed it, I don’t want that to happen.

I have ordered the intake to head gaskets x2 (orange) as well and 1 throttle body gasket. Do I need to replace the water bypass gasket? If so, how many do I need to order on those water bypass gaskets? And do I need to drain my coolant from the radiator if I will be replacing the water bypass gasket? Thanks again need all the help I can get, most parts people from the dealership will get lost with these from my experience.

Here are the photos that seemed unusual for me seeing traces of seepage:

I want to rule this out from a minute reason leading to a P0430 (bank2 lean AF caused by oil or fluid or air leak. For those who run a VVTi LC or LX, I strongly urge for you to check these as well as an ounce of prevention is worth a pound of cure.

 

[2001LC]

Seepage on plastic does look like oil, which comes from PCV passing shrunken gasket during/after cool down. You'll find more on underside of intake manifold when you pull it.

If you separate throttle body from manifold and leave it in place, you'll not need to drain coolant. IIRC it just has 1 coolant line attached to throttle body on VVT. Don't disconnect it and no need to drain coolant. VVT's having a plastic manifold, makes it very lite with T-body disconnect, so sweet compared to older non VVT.

The water bypass joints do not need to be resealed if not leaking. Some like to do while in there. They are cheap and easy. You'll need to drain off one gallon form block (1/2 gallon from each side of block) and 1 gal from radiator if you do these.

Now if you're a "while in there kind of guy". The A.I. system and starter will stare back at you.

Note: Disconnect main fuel line at fuel filter and leave on fuel rail. Just thread it out as you pull manifold.

 

[OEMGUY0720]

The road to P0430 continues..

My needed parts came in:
• Intake Manifold Gaskets L&R side
• Throttle Body Gasket,
• Injectors O-ring gasket:

Intake ports now accessible. All gunked up and dirty, I bet sin 06 this hasn’t been serviced. Intake ports covered from particles accidentally going inside.

Intake port, BEFORE:

Intake port AFTER:

 

[OEMGUY0720]

Broke the Coolant Temperature Sensor by accident
Called O’Reilly I was in luck they have one.

 

[2001LC]

I should have warned you to clean engine before pulling intake. You can also vacuum the cylinders that intake valves were open through spark plug holes.

If you can let sit for week or two. Now's good time to send fuel injectors out the be tested and rebuilt. I say this because you purchased Fuel Injector (FI) O-rings. So that means your pulling FI's The rials can be pulled I suppose without remove each side separately. But if you do break down each side as I do. You'll need the gasket/washer for the rails and Fuel crossover pipes. The damper has the odd-ball gasket/washer.

This would give you time to get OEM water temp sensor.

Oh no, that starter is just looking at you How many miles on the clock...LOL

 

[OEMGUY0720]

I should have warned you to clean engine before pulling intake. You can also vacuum the cylinders that intake valves were open through spark plug holes.

If you can let sit for week or two. Now's good time to send fuel injectors out the be tested and rebuilt. I say this because you purchased Fuel Injector (FI) O-rings. So that means your pulling FI's The rials can be pulled I suppose without remove each side separately. But if you do break down each side as I do. You'll need the gasket/washer for the rails and Fuel crossover pipes. The damper has the odd-ball gasket/washer.

This would give you time to get OEM water temp sensor.

Oh no, that starter is just looking at you How many miles on the clock...LOL

Hey Paul, I'm really considering that starter! But it's working fine as of now, it turns up pretty well still for it's miles, would just work on it "when the time comes" I know its a PITA but heck at least I know next time how to remove this faster right? lol.
The fuel injectors too, they are still at optimal performance, I'd work on them next time maybe even upgrade to a different one with more holes/jettings on it. I pulled them earlier along with the fuel rail before I took out the entire intake manifold as it is on the way and blocking the upward removal of the IM. Before leaving for O'Reillys, I inspected one of the FIs, and saw the rubber o-ring seals was cracked (will post picture tomorrow), so while at it, I asked if they have -and gave me the Dorman ProPack O-rings set.

Did you pushed through rebuilding your FIs? What shop did you send it to? Details?
Yup I used a vacuum cleaner for those bigger debris in the intake manifold area, worked like a dream. Then unlimited cucles of brusing the surface using a toothbrush and carb cleaner to soften the crusty dirt with oil deposit on it until the aluminum surface came up (will also post pictures tomorrow).

 

[2001LC]

If any concern with grit in IM ports. I'd consider floating something perhaps ATF into cylinder that valve were open and wet vacuuming out. I'd do this two or three times. Also do the ports of IM. Last float, use 0W-10 oil or some light engine oil. Once done crank engine with spark plugs out, to blow out remains oil, that vacuum may have not gotten. This may sound excessive and it is. But any abrasive in the ports on valves seats or cylinders walls can cause compression issues down the road. As a young man in mechanic school, my instructor wouldn't even allow us to touch cylinder walls or bearing with a rag, air only. It's more important when rebuilt and seating new rings and bearings. But it why we run with air filters.

I just diagnosed and engine that owner and I feel his not cleaning engine pre pulling IM, cause lose compression in #2 & #8. Will be replacing engine. It was the extreme case and not the norm, but it does happen. Diagnosing P0115, PO300, P0302 & P0308

I've had FI sets rebuilt a number of times. In the link I provide (in-bedded) above and will here again. You'll see pictures of before and after.

Chuck at FIS rejects more FIs than anyone in the world, he's very meticulous. Chuck believe the spray patterns is key to good gas mileage. He's always found some of my FI's with bad patterns. Which cleaned & rebuilding has corrected in all I've had done. We've also had some in which the leak down rate that was to high. Which results in long crank on start. Those we replaced the whole set.

Yeah, I was just playing with you on the starter. When you replace, best is Denso rebuilt off Amazon usually about $120. You can not buy plunger and contacts, just whole magnetic solenoid in 03-07 series 100. Which those cost near the same as a Denso re-man. I do replace the insulator (PN# in-bedded) at bottom of FI in the IM, sometimes in prep for near term future FI cleaning or if FI's pulled.

When to Clean or Replace fuel injectors

Please post your experiences and thoughts on the subject. I’ve been considering cleaning or even replacing all 8 fuel injectors, is this wasting time and money. I understand keeping fuel injector clean by adding a can of additive to the gas tank, now & then, is a good practice. This keeps them...

forum.ih8mud.com

He's something you may try before replacing CAT. Use a CAT cleaner then something like 44K, Chevron Techron or what have you. As you do and afterword, do a cook off. That is Run on HWY at around 5,000 RPM for 5 minutes or longer. Then drop RPM back and cruise, until cools back down and repeat. This is like turning Oven to Clean. It super heats the CATs. Make sure you've got good oil and work your way up to RPM testing engine as you go.

 

[OEMGUY0720]

Continued..
Done with Intake Ports and surrounding area,

Clean and serviced.

I noticed the bolt on the valve cover on the driver side were loose, I was able to turn just with my fingers those bolts - I think that’s the main reason why there’s oil seepage on the valve covers at the driver’s side.

Now on to the intake manifold..

 

[2001LC]

@OEMGUY0720 Can you post a pictures here of hose(s) you're concerned about where/they attach?.

 

[OEMGUY0720]

@2001LC this is the hose I am lost where to connect:

Could this be where to connect it?

Thanks Paul.

 

[2001LC]

Yes that is where it goes. If you've forceps, it's possible to slip on with intake on engine.

 

[OEMGUY0720]

Got it. Thanks! I also verified thru different illustrations from the links you gave partsouq and toyotaparts.

Engine is running now and so far P0430 (CEL) hasn’t come up except for the blinking VGRS which I understand because of disconnecting the battery for more than 5 minutes.

 

[2001LC]

In the LX VGRS will do that. Just drive in straight line at 35 MPH a few 100 yards. VGRS light goes off. Book then states do right and left turns. I do double figure eights.

If CEl still on (VGRS should be off after above) clear all codes. Then see if any come back.

 

[OEMGUY0720]

Update:
Cleaned the:
• intake manifold assembly
• cleaned the throttle body
• cleaned 8 fuel injectors

Replaced (all with new oem parts):
• intake manifold gaskets
• throttle body gasket
• fuel injector (8) o-ring seals

CEL with P0430 still comes up. So I’moving to the actual CAT replacement, this time not OEM to save up on $$$.

Made in Canada, got from eBay one of those cheap ones interesting to see if this will work for a good amount of time.

So my next questions are:
• the O2 sensor port doesn’t have a welded bung on it, it’s flange type. What is the correct size I should get and where to best get one?
• the O2 sensor port is now moved rearward on this aftermarket catalytic converter, the oe is located in the mid part so the wire reaches it without any problems, this one the oe/l or even denso O2 sensor wire is too short and there’s no way it would reach that port/hole - question is: will I cut and solder the wires and extend it?

Regards,
Paul

 

[jerryb]

since you're in for 500 on sensors and need, or should, weld a bung in, I would do it where they need to be so you're not extending wires. I would not extend the wideband wires for any reason. The rear narrow band ones I would extend. But sheesh, I'm sorry you spent that.
I haven't verified but m18 x 1.5