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P0420 - Replaced Cat and 02 sesnor, this thing won't go away.


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2 hours ago, phyregold said:

 

How do you trick the system if the 02 won't come ready?  Or are you suggesting putting the 02 back the way it was resetting everything and moving forward?

yes get rid of the spacer, clear codes (did you buy that cheap code reader/eraser yet?) and see if the 0440 stays off then see if you can get the systems "ready".

I can get my systems ready by following a procedure: gas tank 1/2 full drive 55 mph for 15 minutes without changing speed or braking. Slow down to 10 mph then accelerate again to 55.

That usually gets the systems ready and then a quick drive right to the inspection station and I'm good for another 2 years. The 0420 is a code that has many possible causes and I refuse to throw my wallet at the great unknown.

Sometimes the CEL goes off by itself but no rhyme or reason as far as I can see.

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On 10/15/2023 at 9:00 PM, brus brother said:

yes get rid of the spacer, clear codes (did you buy that cheap code reader/eraser yet?) and see if the 0440 stays off then see if you can get the systems "ready".

I can get my systems ready by following a procedure: gas tank 1/2 full drive 55 mph for 15 minutes without changing speed or braking. Slow down to 10 mph then accelerate again to 55.

That usually gets the systems ready and then a quick drive right to the inspection station and I'm good for another 2 years. The 0420 is a code that has many possible causes and I refuse to throw my wallet at the great unknown.

Sometimes the CEL goes off by itself but no rhyme or reason as far as I can see.

So, I took off the 02 sensor and cleaned it, for some reason it has some oil on it.  I'm going to guess I have a leak in my oil pain...

 

When I cleaned it and put the 02 sensor back in, and drove it like you suggested.  When I did that, the 02 sensor came ready and guess what!  No P0420, now I'm going to guess I got the P0420 from oil getting on the sensor?

 

The only bad news is the CAT and the EVAP have yet to come ready, so I'm hoping I don't get the P0440 back...

 

image.jpeg.d6fe7d8b6b12bf70fc6a2cd372c91d8b.jpeg

 

Edited by phyregold
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But the oil wasn't on the internal aspect of the spacer?/ If there was oil internally, that cat is in trouble!

Fingers crossed. at least 0440 gremlin s gone ... for the moment.

I recall reading somewhere that you can pass with 1 (one) system not ready but I don't have first hand knowledge.

Don't be discouraged if the 0420 returns as you haven't really done anything that would have cured the P0420. You likely just backed out of the 0440.
P0420 is a real bugger but you can reset using your fancy new code reader (?) and hope you clear and set systems ready then scurry over to pass emissions inspection.

We get a warning post card about 2 months before inspections become due so I have time to try and cheat the system.

Just sit tight now and don't be tempted to do a reset as you will go back to having all the systems needing to reset. 

With the cel on, the cruise control doesn't work and a few dash lights are flashing but if it bothers you, a piece of black electric tape will cover the light 😉  

Keep us posted

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1 hour ago, brus brother said:

But the oil wasn't on the internal aspect of the spacer?/ If there was oil internally, that cat is in trouble!

Fingers crossed. at least 0440 gremlin s gone ... for the moment.

I recall reading somewhere that you can pass with 1 (one) system not ready but I don't have first hand knowledge.

Don't be discouraged if the 0420 returns as you haven't really done anything that would have cured the P0420. You likely just backed out of the 0440.
P0420 is a real bugger but you can reset using your fancy new code reader (?) and hope you clear and set systems ready then scurry over to pass emissions inspection.

We get a warning post card about 2 months before inspections become due so I have time to try and cheat the system.

Just sit tight now and don't be tempted to do a reset as you will go back to having all the systems needing to reset. 

With the cel on, the cruise control doesn't work and a few dash lights are flashing but if it bothers you, a piece of black electric tape will cover the light 😉  

Keep us posted

Okay the P0420 just came back just after I wrote that post.

 

The EVAP isn't ready yet so no idea if the P0440 will come back.  I'm not entirely sure if the oil was on the inside of the spacer, it didn't appear so...

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Here is the 02 sensor, it doesn't look terribly dirty.

02sensor.PNG.4d678519201f1bb141e0d4822a5a3e5c.PNG

 

This is where the oil leak I have is coming from, it was running down on the 02 sensor wire, i'm assuming this is a pan issue...

oil.png.fae1d2785878e09c107c2695e987f034.png

This is where we drilled it

bottom.jpg.7e019ba125b0de8e789ae57e59030693.jpg

 

this is the exhaust

20231017_211511.jpg.0e5be8d1310535bdcd2a4338644d8aa9.jpg

 

Maybe I should have drilled the spacer all the way through?

20231017_211335.jpg.1135cf5e12477356f13ca809571f0298.jpg

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On 10/17/2023 at 9:41 PM, phyregold said:

Here is the 02 sensor, it doesn't look terribly dirty.

02sensor.PNG.4d678519201f1bb141e0d4822a5a3e5c.PNG

 

This is where the oil leak I have is coming from, it was running down on the 02 sensor wire, i'm assuming this is a pan issue...

oil.png.fae1d2785878e09c107c2695e987f034.png

This is where we drilled it

bottom.jpg.7e019ba125b0de8e789ae57e59030693.jpg

 

this is the exhaust

20231017_211511.jpg.0e5be8d1310535bdcd2a4338644d8aa9.jpg

 

Maybe I should have drilled the spacer all the way through?

20231017_211335.jpg.1135cf5e12477356f13ca809571f0298.jpg

Maybe.  I'll try to remember to look at mine at home, but it'll be a busy night so I might not get to it. 

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I took the vehicle to Scotty Muffler, and they told me they think I need to replace both the Front cat and the front o2 sensor. They believe the front cat isn't going a good enough job and that the back cat was replaced with an OEM cat..

 

1400$ qoute... i feel like this isn's right

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4 hours ago, phyregold said:

I took the vehicle to Scotty Muffler, and they told me they think I need to replace both the Front cat and the front o2 sensor. They believe the front cat isn't going a good enough job and that the back cat was replaced with an OEM cat..

 

1400$ qoute... i feel like this isn's right

I wouldn't jump in. Are you due for emissions testing? If you have some time, play around with trying to get the systems ready to pass inspxn. and if you get the hang of the handshake, drive it into the ground. That's what I did for 8 years after P0420 afflicted my 05 OB passing inspection every 2 years.

That's a lot of $ on an older car with possible issue with your Frankenstein motor swap.

And, it might not solve the problem. How sure is ole Scotty of his call and will he guarantee it and for how long?

There is a way of flashing the ecu to eliminate the code but you didn't hear it from me. It's illegal and I don't know a guy...

BTW is P0440 still gone?

Edited by brus brother
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On 10/19/2023 at 2:01 PM, idosubaru said:

Maybe.  I'll try to remember to look at mine at home, but it'll be a busy night so I might not get to it. 

Sorry I forgot to check. I wont' have access to my parts stash until Sunday/Monday. 

 

8 hours ago, phyregold said:

I took the vehicle to Scotty Muffler, and they told me they think I need to replace both the Front cat and the front o2 sensor. They believe the front cat isn't going a good enough job and that the back cat was replaced with an OEM cat..

 

1400$ qoute... i feel like this isn's right

They're guessing, I would avoid that unless you are desperate and have no choice but to gamble with 4 digits of cash to pass that lame emissions.

 

4 hours ago, brus brother said:

 

There is a way of flashing the ecu to eliminate the code but you didn't hear it from me. It's illegal and I don't know a guy...

This is the way. lol Being a 4 cylinder all the work has probably already been done and maps are already out there for you.  but it is techy and dense to dive into. 

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8 hours ago, phyregold said:

I took the vehicle to Scotty Muffler, and they told me they think I need to replace both the Front cat and the front o2 sensor. They believe the front cat isn't going a good enough job and that the back cat was replaced with an OEM cat..

 

1400$ qoute... i feel like this isn's right

The Subaru converter for your car is $1,300 from Subaru, so sounds like they might be pricing a new bolt on unit from Subaru. Which has a really good chance of making the light go out.  Do you know if they were quoting a new Subaru part or something else?  If I was spending $1,400 it would only be for the Subaru part, no way I'm paying that for aftermarket converters.

Which O2 sensors have been replaced so far and were they plug and play or wired in? 
Hopefully the right sensor is in the right location and they were wired properly if they're the generic loose wire variety.

I'd also probably gamble on this:  https://www.fastwrx.com/products/oxygen-sensor-spacer-with-cat

Never used one myself, but for $50 looks awesome.  it's like a mini converter right before your O2 sensor. 

If you're going to replace exhaust - it doesn't hurt to ask around and get a second opinion. 

 

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16 hours ago, brus brother said:

I wouldn't jump in. Are you due for emissions testing? If you have some time, play around with trying to get the systems ready to pass inspxn. and if you get the hang of the handshake, drive it into the ground. That's what I did for 8 years after P0420 afflicted my 05 OB passing inspection every 2 years.

That's a lot of $ on an older car with possible issue with your Frankenstein motor swap.

And, it might not solve the problem. How sure is ole Scotty of his call and will he guarantee it and for how long?

There is a way of flashing the ecu to eliminate the code but you didn't hear it from me. It's illegal and I don't know a guy...

BTW is P0440 still gone?

 

Okay, so the p0440 is gone and the p0440 only appeared with the spacer.  I actually have all the sensors ready and 1 code now (the P0420).  The problem with the spacer is the 02 sensor never came ready.

image.jpeg.73ce9005e1d1d5c4c74b51bb8b3c9845.jpegimage.jpeg.5d7168543b3398b17c4f5d21bbea0af2.jpeg

 

11 hours ago, idosubaru said:

The Subaru converter for your car is $1,300 from Subaru, so sounds like they might be pricing a new bolt on unit from Subaru. Which has a really good chance of making the light go out.  Do you know if they were quoting a new Subaru part or something else?  If I was spending $1,400 it would only be for the Subaru part, no way I'm paying that for aftermarket converters.

Which O2 sensors have been replaced so far and were they plug and play or wired in? 
Hopefully the right sensor is in the right location and they were wired properly if they're the generic loose wire variety.

I'd also probably gamble on this:  https://www.fastwrx.com/products/oxygen-sensor-spacer-with-cat

Never used one myself, but for $50 looks awesome.  it's like a mini converter right before your O2 sensor. 

If you're going to replace exhaust - it doesn't hurt to ask around and get a second opinion. 

 

The rear sensor and the rear cat have been replaced.  The front cat is the original 22 year old part.  I called another shop up north and they will replace the front cat with the direct bolt-on for 900$ including the 02.  The "gig" with Scotty Muffler is they are certified by the state, they said for 2500$ of work if they don't get the light to go off they can certify the car and the state will accept it.  But I'd have to get that 2500$ of work every 2 years.

 

And yeah, this Frankenstein swap is a PoS, the shop that I wanted to do the work told me they couldn't get the 2.2 and they said the 2.5 would not be a problem, I've been stuck with this issue since...

 

I just found it really super odd the o2 sensor would not come ready with a spacer and gave me P0440...

If I put the spacer on now will the light just turn off or do I have to clear the codes?

I feel like I need to find a shop who can actually hook it up to a machine and measure the o2 somehow, the actual flow or electricity and know what they are talking about, but honestly I don't even know what test I'd be asking for.  this guy demos the test in his video.  I hate to pay the 900$ and the front cat isn't the problem...

 

 

May I should put the spacer on the front sensor (this is a stupid question - ignore this)

Edited by phyregold
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1 hour ago, phyregold said:

 

Okay, so the p0440 is gone and the p0440 only appeared with the spacer.  I actually have all the sensors ready and 1 code now (the P0420).  The problem with the spacer is the 02 sensor never came ready.

image.jpeg.73ce9005e1d1d5c4c74b51bb8b3c9845.jpegimage.jpeg.5d7168543b3398b17c4f5d21bbea0af2.jpeg

 

The rear sensor and the rear cat have been replaced.  The front cat is the original 22 year old part.  I called another shop up north and they will replace the front cat with the direct bolt-on for 900$ including the 02.  The "gig" with Scotty Muffler is they are certified by the state, they said for 2500$ of work if they don't get the light to go off they can certify the car and the state will accept it.  But I'd have to get that 2500$ of work every 2 years.

 

And yeah, this Frankenstein swap is a PoS, the shop that I wanted to do the work told me they couldn't get the 2.2 and they said the 2.5 would not be a problem, I've been stuck with this issue since...

 

I just found it really super odd the o2 sensor would not come ready with a spacer and gave me P0440...

If I put the spacer on now will the light just turn off or do I have to clear the codes?

You should be able to just put the spacer in and let it rectify itself and the light goes out. 

i routinely install the spacer and clear the code immediately because ivE never had issues with the monitors being ready. 
 

but yours seems different and doesn’t respond as we are expecting  

Your issues may be swap related somehow. You should easily be able to swap those motors with no issues. EJ25 swapped into EJ22 vehicles has been done thousands of times and those spacers are well known work arounds for pre 2005 Subarus.  That’s why brusborthers wouldn’t work - his was a 2005 and that’s when immobilizer CANBUS and the O2 data starts to get used by the fuel injection. It’s much more sensitive. 

In 2004 and earlier the rear sensor is just a trigger for the P0420 code. You can completely disconnect the sensor and the car runs fine. Can’t do that 2005+. But clearly you have issues so it makes me wonder what all happened during that swap?
 

 

 

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1 hour ago, idosubaru said:

You should be able to just put the spacer in and let it rectify itself and the light goes out. 

i routinely install the spacer and clear the code immediately because ivE never had issues with the monitors being ready. 
 

but yours seems different and doesn’t respond as we are expecting  

Your issues may be swap related somehow. You should easily be able to swap those motors with no issues. EJ25 swapped into EJ22 vehicles has been done thousands of times and those spacers are well known work arounds for pre 2005 Subarus.  That’s why brusborthers wouldn’t work - his was a 2005 and that’s when immobilizer CANBUS and the O2 data starts to get used by the fuel injection. It’s much more sensitive. 

In 2004 and earlier the rear sensor is just a trigger for the P0420 code. You can completely disconnect the sensor and the car runs fine. Can’t do that 2005+. But clearly you have issues so it makes me wonder what all happened during that swap?
 

 

 

All fantastic points and questions, the only thing I know of is the exhausted couldn't be correctly put together because it had way to much rust.   I remember the check engine light was on before the 2.2 blew, but I have no idea what it was. 

I'll try the spacer again since all the sensors are ready and see if I can do the drive 55 and then coast to 10 and check if the check engine disappears.  I'll let you know in a few hours.

 

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5 hours ago, idosubaru said:

You should be able to just put the spacer in and let it rectify itself and the light goes out. 

i routinely install the spacer and clear the code immediately because ivE never had issues with the monitors being ready. 
 

but yours seems different and doesn’t respond as we are expecting  

Your issues may be swap related somehow. You should easily be able to swap those motors with no issues. EJ25 swapped into EJ22 vehicles has been done thousands of times and those spacers are well known work arounds for pre 2005 Subarus.  That’s why brusborthers wouldn’t work - his was a 2005 and that’s when immobilizer CANBUS and the O2 data starts to get used by the fuel injection. It’s much more sensitive. 

In 2004 and earlier the rear sensor is just a trigger for the P0420 code. You can completely disconnect the sensor and the car runs fine. Can’t do that 2005+. But clearly you have issues so it makes me wonder what all happened during that swap?
 

 

 

 

 

Alright, so I put the spacer back on and then drove it about 30 miles and did the same thing which seems to bring the O2 sensor ready and nothing happened.  So I stopped by Autozone and picked up Cat Complete Fuel, Exhaust & Emissions System Cleaner and nothing happened.  I drove about 45 miles to go pick up my daughter, shut the car off and turn it back on, and... the light was gone!!

 

So I decided to check it with the scanner but the scanner still found the code!  My check engine light still works because i turn the key over and it lights up, but with the car running, it's gone.  I'm so confused...

 

 image.png.37bdc0ac99b3e29ded3663b46fd45bb0.png

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I think it is normal that light being on with key in on position but goes off with car started?

If the 2.5 came from a MY 05+ that might explain why the spacer trick doesn't work? You aren't sure where the 2.5 came from right?
I seem to remember someone stating a number less than $2500 worth of unsuccessful repairs that gets you past inspection but don't quote me.

Just checked in CT as of 2021 it is $1069 by a certified mechanic. 

In Delaware (you?) see https://www.dmv.de.gov/forms/veh_serv_forms/pdfs/D19477_ve_inspection_pro.pdf

looks like it's $710 see section 3 in above link.

Edited by brus brother
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39 minutes ago, brus brother said:

I think it is normal that light being on with key in on position but goes off with car started?

If the 2.5 came from a MY 05+ that might explain why the spacer trick doesn't work? You aren't sure where the 2.5 came from right?
I seem to remember someone stating a number less than $2500 worth of unsuccessful repairs that gets you past inspection but don't quote me.

Just checked in CT as of 2021 it is $1069 by a certified mechanic. 

In Delaware (you?) see https://www.dmv.de.gov/forms/veh_serv_forms/pdfs/D19477_ve_inspection_pro.pdf

looks like it's $710 see section 3 in above link.

 

Just to make sure we're on the same page.  The engine light is off when the car is running.  I only mentioned the check engine light was on because I was making sure the check engine light bulb worked.

 

So the check engine light is gone, the check engine light bulb works, when I scan the car when the car is running the p0420 is still there.

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1 hour ago, phyregold said:

So the check engine light is gone, the check engine light bulb works, when I scan the car when the car is running the p0420 is still there.

the code will be there as a "stored code" until it is cleared by the reader/scan tool
the light off means the problem has been resolved, and that is all that matters

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58 minutes ago, heartless said:

the code will be there as a "stored code" until it is cleared by the reader/scan tool
the light off means the problem has been resolved, and that is all that matters

Heartless, are you sure it is a "stored code' or is it "pending" and waiting for the next check to trip the P0420 code?

My reader actually called it "pending" but I was using the very expensive $19 reader 😉

As I recall, if you use the scan tool or disconnect the battery to erase the code, you will likely have to again wait for systems to become ready.

Edited by brus brother
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3 hours ago, brus brother said:

 

If the 2.5 came from a MY 05+ that might explain why the spacer trick doesn't work?

Good suggestion but 2005+ OB/Legacy has VVT and wouldn't be interchangeable (without very significant effort). Also, the ineffectiveness of the spacer should be due to 2005+ ECU software changes rather than engine changes.

 

4 hours ago, phyregold said:

 

So I decided to check it with the scanner but the scanner still found the code!  My check engine light still works because i turn the key over and it lights up, but with the car running, it's gone.  I'm so confused...


Does it say "pending"?  Or do you just click "READ CODES" and it shows that code with no other information? 

Maybe it's seeing a code from memory?   

Ideally you clear the codes first.  Then do your preliminary drive as brusbrothers stated.  Then check the codes. This ensure they are indeed new codes. 
I hate to say it - but can you clear and do one more drive?!

 

1 hour ago, heartless said:


the light off means the problem has been resolved, and that is all that matters

Not all the time, there are "Pending" codes.  It's best to clear first, run, then read. And ideally tell us how the scanner is working (read/memory/pending/etc) since each scanner has different user textual interfaces. One of mine even has a rudimentary GUI to start.

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10 hours ago, idosubaru said:

Good suggestion but 2005+ OB/Legacy has VVT and wouldn't be interchangeable (without very significant effort). Also, the ineffectiveness of the spacer should be due to 2005+ ECU software changes rather than engine changes.

 


Does it say "pending"?  Or do you just click "READ CODES" and it shows that code with no other information? 

Maybe it's seeing a code from memory?   

Ideally you clear the codes first.  Then do your preliminary drive as brusbrothers stated.  Then check the codes. This ensure they are indeed new codes. 
I hate to say it - but can you clear and do one more drive?!

 

Not all the time, there are "Pending" codes.  It's best to clear first, run, then read. And ideally tell us how the scanner is working (read/memory/pending/etc) since each scanner has different user textual interfaces. One of mine even has a rudimentary GUI to start.

 

Okay, so it's a stored code that doesn't see a fault anymore, it's not "pending".  This will still cause me to fail inspection.

 

I'm going to clear the codes which will cause everything to become unready... but, maybe the difference is yesterday when I had to go pick up my daughter yesterday I was able to do  80 the entire way.  This might be a difference because I typically only do 55-60 everywhere and my working theory is, if the spacer is indeed causing the sensor to not get enough information, then going 80 with the additional exhaust flow might have caused the sensor to  receive enough information.....?

 

Going to clear the codes and try again... 

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Hah!  Working theory proven.  The spacer I'm using was unable to get all the information needed at 55, so when I did 80 to pick her up the exhaust must be able to push enough up to it...

 

Now, I'm not sure why I was getting the random P0440 when the spacer was used, but wasn't when the spacer wasn't used.  So what do I need to do to get the evap to come ready?

image.png.2eb8934a70c524428099007940ea5881.png

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Diagnosis is tricky and can be challenging. This therefore that until... oh wait! Never mind.

IIRC the evap was the last to become ready on my 05 OB.

So is the spacer still in place?

If the evap stays shitz, wasn't there discussion earlier about checking out evap system components located somewhere aft?

:popcorn: waiting for the end credits to roll before I leave the theater.

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1 minute ago, brus brother said:

Diagnosis is tricky and can be challenging. This therefore that until... oh wait! Never mind.

IIRC the evap was the last to become ready on my 05 OB.

So is the spacer still in place?

If the evap stays shitz, wasn't there discussion earlier about checking out evap system components located somewhere aft?

:popcorn: waiting for the end credits to roll before I leave the theater.

 Spacer is attached yes, all sensors are ready except for EVAP and currently have 0 codes.

 

So, now I just need to get the evap ready...

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