p0420 & p0430 on volvo xc90 2012 Topic is solved

[chitownV]

It’s your XC90 and you have to figure some things out yourself. Take pics of the New cats, down pipes, since these are where the O2 sensors are.

Taking pictures, simply smelling the oil, and sharing what you personally have done since a mechanic can tell you anything. These were requested months ago since you are personally there seeing, hearing, and smelling your XC90.

Also, list detailed parts changed, when, and other relevant work done. If the cats were changed, were the gaskets changed too? Don’t assume here. Or was an exhaust paste used, or did they reuse the old gaskets?.

If you have an oil leak, you want to take care of that before increasing the oil viscosity that would suit an older 5cyl better. I have a tuned turbo BMW with ~400hp & 425 ft/lbs and I get it about the oil. Still contemplating a larger turbo. Rotella T6 did change its oil formula since 2012. It has less zinc and is thinner IIRC. I’ve also helped/worked on numerous P2 & P3 2.5t engines.

I’ve directly helped over two dozen 3.2 owners sort through their P0420/P0430 codes. I don’t help everyone because it takes work on your part to communicate and get your hands dirty. Patience is required.

This is internet diagnosing and you have to do your own work. You have to verify, not assume, each part is good, verify the common high mileage maintenance parts are good and changed with trusted brands, and verify each “repair or fix” is correctly done.

The #1 cause of issues are related to lack of or poor maintenance. Poor maintenance includes repairs and fixes not being done correctly or using subpar parts that continue to cause issues.

[MoVolvos]

How do i use this Lacquer Thinner?

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If you know the oil consumption is high and the weather is warm at this time, use Rotella T6 15W40 as 0W40 is too thin for your problem. The Rotella will clean and provide a thicker film so less blowby. You also need to clean the CATS. If you aren't already start using Premium fuel.
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ChitownV provided good info so don't disregard it. Do this and if it improves you know the CAT is contaminated already. Till tomorrow.
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[EgoziAlon]

Has anyone of you ever used this thiner? It can't do any harm to the engine?

[MoVolvos]

Has anyone of you ever used this thiner? It can't do any harm to the engine?

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I've forgotten how far back this topic went.

viewtopic.php?p=562306&hilit=lacquer+thinner#p562306

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[chitownV]

Just a consideration, if an engine running and maintenance issue is causing the oil accumulation in the catalytic converters and contributing to the P0420/P0430 codes, the engine issues should be fixed first. Since brand new catalytic converters were already installed, if the paint thinner helps clean the cats, this problem will return without fixing the engine issues.

We always start with the known (high-mileage) maintenance first so that new catalytic converters don’t get contaminated. Doing the paint thinner also won’t solve an oil consumption issue, or white accumulation on the spark plugs, or oil burning smell in the engine bay.

[EgoziAlon]

Just a consideration, if an engine running and maintenance issue is causing the oil accumulation in the catalytic converters and contributing to the P0420/P0430 codes, the engine issues should be fixed first. Since brand new catalytic converters were already installed, if the paint thinner helps clean the cats, this problem will return without fixing the engine issues.

We always start with the known (high-mileage) maintenance first so that new catalytic converters don’t get contaminated. Doing the paint thinner also won’t solve an oil consumption issue, or white accumulation on the spark plugs, or oil burning smell in the engine bay.

Exactly!

But the problem is that i don't have a Clue what is the problem.
Maybe it is the rings... And then i don't have anything to do besides exchanging the engine

[EgoziAlon]

It’s your XC90 and you have to figure some things out yourself. Take pics of the New cats, down pipes, since these are where the O2 sensors are.

Taking pictures, simply smelling the oil, and sharing what you personally have done since a mechanic can tell you anything. These were requested months ago since you are personally there seeing, hearing, and smelling your XC90.

Also, list detailed parts changed, when, and other relevant work done. If the cats were changed, were the gaskets changed too? Don’t assume here. Or was an exhaust paste used, or did they reuse the old gaskets?.

If you have an oil leak, you want to take care of that before increasing the oil viscosity that would suit an older 5cyl better. I have a tuned turbo BMW with ~400hp & 425 ft/lbs and I get it about the oil. Still contemplating a larger turbo. Rotella T6 did change its oil formula since 2012. It has less zinc and is thinner IIRC. I’ve also helped/worked on numerous P2 & P3 2.5t engines.

I’ve directly helped over two dozen 3.2 owners sort through their P0420/P0430 codes. I don’t help everyone because it takes work on your part to communicate and get your hands dirty. Patience is required.

This is internet diagnosing and you have to do your own work. You have to verify, not assume, each part is good, verify the common high mileage maintenance parts are good and changed with trusted brands, and verify each “repair or fix” is correctly done.

The #1 cause of issues are related to lack of or poor maintenance. Poor maintenance includes repairs and fixes not being done correctly or using subpar parts that continue to cause issues.

I smelled the oil
I think it does have a little bit smell of fuel - like a little bit volatile. Maybe a little bit sweat.
About parts that were changed - i have no idea what was done before i owned it. After i bought the car - i wrote in opening.
I don't know if they replaced the gaskets while fixing the converters - my guess is that they didn't. I will try and ask tomorrow.

[EgoziAlon]

I will try and check tomorrow the plugs.
Anything else to look at?
What about live data from my scanner?

[chitownV]

Just a consideration, if an engine running and maintenance issue is causing the oil accumulation in the catalytic converters and contributing to the P0420/P0430 codes, the engine issues should be fixed first. Since brand new catalytic converters were already installed, if the paint thinner helps clean the cats, this problem will return without fixing the engine issues.

We always start with the known (high-mileage) maintenance first so that new catalytic converters don’t get contaminated. Doing the paint thinner also won’t solve an oil consumption issue, or white accumulation on the spark plugs, or oil burning smell in the engine bay.

Exactly!

But the problem is that i don't have a Clue what is the problem.
Maybe it is the rings... And then i don't have anything to do besides exchanging the engine

Nobody knows! Certainly nobody here who doesn’t have the vehicle in front of them. This is where you have to be patient and listen. This is the first time you smelled your oil and took pictures in months of asking. Don’t guess as you are guessing they didn’t change the gaskets. You have to verify!

Now, take it slow before jumping into something else. You finally posted pictures. Evaluate, reassess, then verify.

The catalytic converters from the heat shield holes for the O2 sensors don’t look like they were changed. They appear dirty and there is some corrosion on one.

Re-read the things posted for you three times slowly. It was also mentioned about the serpentine, decoupler area, and downpipes. What if they replaced the downpipes/secondary catalytic converters? I was trying to help you on the other forum about getting to this. You should probably also post back to that forum since it has the history.

Take pictures closer to the decoupler area, closer to the serpentine, stick your phone under the drivers seat area and take pictures of the catalytic converters. Verify…..

Also, it looks like you are leaking oil from the PCV seal and leaking from the PCV diaphragm cap. These are issues. Maybe leaking oil from a sensor o-ring which isn’t an issue, just needs to be changed when you can.

If you are smelling something in the oil, then it’s an issue. Even if it’s smelling burnt at low miles/kilometers, you could be running both lean and rich.

Also, I see your engine is very dirty. Double check the air filter as that should be changed more often.

There’s so much more…..

[MoVolvos]

Just a consideration, if an engine running and maintenance issue is causing the oil accumulation in the catalytic converters and contributing to the P0420/P0430 codes, the engine issues should be fixed first. Since brand new catalytic converters were already installed, if the paint thinner helps clean the cats, this problem will return without fixing the engine issues.

We always start with the known (high-mileage) maintenance first so that new catalytic converters don’t get contaminated. Doing the paint thinner also won’t solve an oil consumption issue, or white accumulation on the spark plugs, or oil burning smell in the engine bay.

Exactly!

But the problem is that i don't have a Clue what is the problem.
Maybe it is the rings... And then i don't have anything to do besides exchanging the engine

.
Exactly! , the problem is that you don't have a Clue what is the problem. You've got to establish a baseline and then test! Going all over the place looking for things unknown without a potential remedy or just replacing parts can get expensive, so is not the way to start.

Changing parts and hoping the code goes away is not diagnostics. Start with the known and it if improves or is gone you're good but if it comes back then you go into the unknowns. Regardless, unless you establish a baseline of no codes you won't know whether anything you do had an effect. Have to clean and clear before doing other things assuming there is root cause or a combination of causes affecting the CAT.

Known:

* CAT was changed and code came back slower.
* Plugs are starting to foul again.
* Problem improved with 0W40.
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First:

* Clean CAT and if code goes away you know it can go away.
* Change oil to 15W40 and see how long before code returns or doesn't return. If the length between code is extended you know it's an oil issue as the or one of the issues.
* At this point you can start to poke around for the unknown and see if you can find something else potentially contributing to the problem.
* Regardless, you have to bring the CAT back to the baseline or else it's wait and see after you decide you want to pursue the unknown(s) and replace parts as a way of diagnosis.
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