P0430

[oljedi11950]

Something I learned back when I 1st joined is that the upstream air/fuel sensor is usually going bad because of the O2 sensor going so it will pop a 0430 or 0420 ! Their a ***** :der: but did mine on the 05 & cleared it up . :thumb: Always start with cheapest & work fwd !

 

[asabs6]

I have an '06 4Runner and about once a week my check engine comes on with the 0430 code. I clear it and it doesn't come back for week. I took the truck in to my local wrench, they said the cat looked good but run some premium gas for a tank or 2 just to clean up any junk. I did that still keeps happening.

Any ideas?

I know your post was over 2 years ago but I'm curious what luck you had and if you can recommend a quality shop in the BoCO or Denver area that could really diagnose the same issue I'm having.


Thanks,
Adam

 

[hubertron]

I know your post was over 2 years ago but I'm curious what luck you had and if you can recommend a quality shop in the BoCO or Denver area that could really diagnose the same issue I'm having.


Thanks,
Adam

Believe it or not, I am still having this issue, and just posted about it again. I have narrowed it down immensely though.

Where does your sensor go off? Is it the same locations?

 

[Dmann]

P0430 / VSC Lights

I've got the P0430 as well as VSC lights, i know i have an Exhaust Leak, gonna have to replace the Exhaust Manifolds, there are lots of different brands to choose from though, such as Bosal, Dorman, Walker, Eastern Catalytic, anyone have any recommendations on one of these?

 

[ajgray925]

P0430 Resolution

I also had the P0430 code on my 2006 4Runner SR5 V6 4WD with 142K miles. I verified the code with my code reader. I've been troubleshooting on the weekends over the past few months and finally figured it out.

In my case, the P0430 CIL code is triggered by the oxygen sensor downstream of the 1st CAT (driver's side on my particular vehicle). There's 4 CATs, but only the 1st two are monitored with O2 sensors (1st on driver's side and 1st on passenger side).

I did the following and the CIL always came back on:

Changed gas cap after reading some forums. Cheap & quick thing to do to rule it out. Didn't help.

Replaced O2 sensor downstream of driver's side CAT. About $85 for the part and installed myself. O2 sensors are 9 years old, so no harm in replacing. Didn't help.

Cleaned MAF sensor. Didn't help.

Ran fuel cleaner. Didn't help.

Replaced air filter. Didn't help.

Checked/cleaned throttle air body. Didn't help.

Checked for vacuum leaks in engine. None found.

Performed the WOT (Wide Open Throttle) test on highway (@ 55mph, press gas pedal to floor and accelerate to about 80+mph). No lack of performance, so I figured my CAT(s) were good and not clogged. Gas mileage has not suffered either which also helped me rule out a bad CAT(s).

I checked for air leaks in the exhaust system, specifically on the driver's side around the CAT. Using a spray bottle with soap, I honestly could not tell if the bubbles were air or just from steam / heat. I don't recommend this method to find leaks in your exhaust.

Finally, after watching youtube videos, I saw a method to easily locate air leaks in the exhaust. I hooked up my shop vac blower (pushing air - not sucking air) to my tailpipe, duct taped it well to the tailpipe, and turned the blower on. Using this method, I easily found 2 leaks in my exhaust. You could definitely hear it and then could feel the air pushing out (obviously make sure exhaust is not hot when you do this!).

One leak was at the driver's side CAT bolted flange location at the downstream side of CAT, immediately before the O2 sensor that I had replaced previously. I had a muffler shop replace the gasket and rusted bolts at that location. I then reset the CIL and haven't seen the light return in over a week.

Evidently, what had been happening is air/oxygen was getting sucked into that exhaust leak after the CAT. There's not supposed to be any Oxygen left after engine exhaust makes it through the CAT, so that was triggering the O2 sensor after the CAT; making it think the CAT wasn't performing properly..but it was.

I also want to point out that every time I reset the CIL, many times it would be triggered during rain, so I think the rain / humidity may have had helped contribute to triggering the O2 sensor at the leak / gasket.

This may not be the exact reason you are getting a P0430 code, but hopefully my experiences will help you narrow down some options to look into. Good luck!

 

[hubertron]

Wow what an awesome response. The rain thing was true for me as well. It sounds like we experienced pretty much the same thing.

I ending up trading my 4Runner in. I had a few other problems with it, and with a kid on the way I wanted something with side impact protection. Thanks for such an awesome response again. I love this community.

 

[Collinrudy]

My 05 v6 is throwing the code also. I did the WOT test to see if the cat was messed up but it seemed fine. I’ve read a couple threads and haven’t quite gotten a concrete answer on if it’s the upstream sensor or downstream. Is there any way to tell which one is possibly messed up? I would typically just replace one or both and see if it fixes it but my dealer quoted me $312 for a new sensor... 312... doesn’t that seem a bit ridiculous? Thanks

 

[SiZ]

They're caused by the downstream 02s (post cat would be the only way that makes sense).

I just had this for the first time after replacing my leaking cats with aftermarket ones on my v8, so a leaking exhaust was out of the question for me.

It cleared up pretty easily with those blox o2 sensor spacers from amazon, that was the fix for me! $20 well spent!

 

[Collinrudy]

Sorry to bring up an old thread but I figured I’d update. I took my 4runner to the dealership and they said it needs a new catylitic converter... gonna be about a grand with parts and labor, maybe another 300 if it needs another O2 Sensor. Lovely.. hope this helps anyone who’s throwing the same code

 

[BIGWIG711]

are all the 02 sensors the same pre and post cat?

anyone got any part numbers?

 

[lightfreak]

are all the 02 sensors the same pre and post cat?

anyone got any part numbers?

Th upstream A/F sensors should be interchangeable but the downstream O2 sensors are different length harness.

Here's what I put in my V6

DENSO 2344804 Downstream Left
DENSO 2344805 Downstream Right

These were like $100 for both from Rockauto
Denso is the OE supplier and side by side comparison they looked exactly the same as the originals; harness length, connector, hole count, etc.


I was only getting the P0420 code periodically the last couple months, changed both downstreams anyway and left the upstreams alone. So far so good in over 600 km

2 buddies are dealership mechanics and they said dealers and independant shops always push for complete manifold job because it's obviously more money for them but also because they don't' want the customer coming back multiple times for the same problem. What they also don't tell you is they get a nice $100 a pop for the used OEM cats that are supposedly bad. :uzi:

 

[BIGWIG711]

Th upstream A/F sensors should be interchangeable but the downstream O2 sensors are different length harness.

Here's what I put in my V6

DENSO 2344804 Downstream Left
DENSO 2344805 Downstream Right

These were like $100 for both from Rockauto
Denso is the OE supplier and side by side comparison they looked exactly the same as the originals; harness length, connector, hole count, etc.


I was only getting the P0420 code periodically the last couple months, changed both downstreams anyway and left the upstreams alone. So far so good in over 600 km

2 buddies are dealership mechanics and they said dealers and independant shops always push for complete manifold job because it's obviously more money for them but also because they don't' want the customer coming back multiple times for the same problem. What they also don't tell you is they get a nice $100 a pop for the used OEM cats that are supposedly bad. :uzi:

im gonna start post cat and work my way up.

I don't see/hear any cracks/leaks in the exhaust system so I'm hoping its the 02 sensors.

I'm amazed they have lasted 250k miles.

 

[Sporin]

Great thread gang, I appreciate all the information as I am chasing a reoccuring P0430 code on my 2005 V6, 186k miles truck.

I picked up a code reader so at least I can reset it and not panic when the Christmas tree lights up.

I replaced the gas cap already with a new OEM one., just a precaution. Light went away for a while, then came back last night after a couple of weeks of clear dash. Cleared the light last night when it came back on and it didn't come back on my short drive today.

So I think whatever is causing it is just on the edge of a problem. The right temps, or maybe the wrong puddle, or whatever. No MPG or Power issues so I think it's probably the downstream O2 sensors going OR a small leak somewhere.

I had some exhaust work done about 3 years ago from my excellent local independent. It's possible I've got a pipe or joint farther up stream from the new stuff with a hole or gasket leak of some sort. I'll have them check this first.

Th upstream A/F sensors should be interchangeable but the downstream O2 sensors are different length harness.

Here's what I put in my V6

DENSO 2344804 Downstream Left
DENSO 2344805 Downstream Right

Thank you for these!! If my muffler shop doesn't find a leak I'll start by replacing these 2 myself.

:vader:

I initially searched up this thread to see how long I could go with this light occasionally coming on. Presumably if it's not happening during my State required yearly inspection, and it's not causing power/mpg issues then it's not something I need to panic about, right? I can clear it when it happens and continue to pick away at possible fixes.

 

[alia176]

Great thread gang, I appreciate all the information as I am chasing a reoccuring P0430 code on my 2005 V6, 186k miles truck.

I picked up a code reader so at least I can reset it and not panic when the Christmas tree lights up.

I replaced the gas cap already with a new OEM one., just a precaution. Light went away for a while, then came back last night after a couple of weeks of clear dash. Cleared the light last night when it came back on and it didn't come back on my short drive today.

So I think whatever is causing it is just on the edge of a problem. The right temps, or maybe the wrong puddle, or whatever. No MPG or Power issues so I think it's probably the downstream O2 sensors going OR a small leak somewhere.

I had some exhaust work done about 3 years ago from my excellent local independent. It's possible I've got a pipe or joint farther up stream from the new stuff with a hole or gasket leak of some sort. I'll have them check this first.



Thank you for these!! If my muffler shop doesn't find a leak I'll start by replacing these 2 myself.

:vader:

I initially searched up this thread to see how long I could go with this light occasionally coming on. Presumably if it's not happening during my State required yearly inspection, and it's not causing power/mpg issues then it's not something I need to panic about, right? I can clear it when it happens and continue to pick away at possible fixes.

There is a nice write up on the previous page about using a shop vac to positively pressurize the exhaust system then look for leaks. You might have a simple leak that's cheap to fix.

 

[Sporin]

There is a nice write up on the previous page about using a shop vac to positively pressurize the exhaust system then look for leaks. You might have a simple leak that's cheap to fix.

Yup, I saw that. I'm going to try it with my leaf blower since my shop-vac is suck-only. :bolt:

 

[cangler]

My v6 with 147k miles just yesterday started throwing the P0430 CEL, first mechanic I've taken it to said needs new cat at $750 without even looking at the vehicle. I passed....was going to take to another mechanic to get 2nd opinion. I sure don't want to waste money replacing the cat if that's not the true problem!

 

[Mr. Banks]

Injection pumps for both banks failure

"Injection pumps for both banks failure and both catalytic deteriorated. Bank 1 catalytic $1,361. Bank 2 catalytic $1,223 air injector pump assy with valves gaskets manifold vsv #1 vsv #2 air tube and switch valve $2,624.

This was all from a pre trip servicing before I drove from Portland OR to San Diego CA. The VSC/trac//abs caution cluster bomb lit up while I was stationed in Okinawa and my mom was driving my 4Runner. The service team is saying this wouldn't be normally this bad but it was ignored and condition only got worse. I don't want to sound all conspiracy theorist, but I just think they're trying to get me when this could be just as simple as a gasket or a sensor. They "strongly advise repairs or new car instead of driving into total failure of air pump"

I work in Naval Aviation and we don't just change engines or transmissions or rotor heads based on a general discrepancy. We troubleshoot and then make repairs before remove/replace.

I'll update once I get the actual code the ECU popped the CEL.

 

[Mr. Banks]

CEL codes

Got the printout and it says my 4runner is throwing P1442, P1445, p0420, 4030, 4040

 

[Whiskey & Wrenches]

I've had my 2004 V6 4Runner for about a year now, so far it has popped up with a P0430 code 3 or 4 times. I would like to do more diagnostics to find out why this is happening, but since the code comes up so infrequently it seems like it isn't worth the trouble. Right now I just clear it with a scanner.

Has anyone else had theirs go months in between tripping a trouble code?

 

[lightfreak]

I've had my 2004 V6 4Runner for about a year now, so far it has popped up with a P0430 code 3 or 4 times. I would like to do more diagnostics to find out why this is happening, but since the code comes up so infrequently it seems like it isn't worth the trouble. Right now I just clear it with a scanner.

Has anyone else had theirs go months in between tripping a trouble code?

Mine was going 2-3 weeks in between.
Here’s what I learned , the computer does a check on the downstream O2s once per key cycle, and only after the cats are nice and hot. So if your driving sessions are short you might not get to the point where the check is done.

You can examine for exhaust leaks first and test cat temps , those are easy and but generally if your going some time in between P0430/P0420 codes it’s most likely the downstream O2.