P0420 cat problem- test pipe?
06-29-2007, 05:11 AM
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P0420 cat problem- test pipe?
I have the all common code P0420- Cat efficiency below threshold. So I searched and didnt find exactly what im looking for. Can I fix the problem with an aftermarket exhaust and a test pipe? Does the test pipe need to have an O2 bung? If it does need an O2 bung, do I use a real O2 sensor or a simulator? Thanks for your help guys
06-29-2007, 05:13 AM
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Re: P0420 cat problem- test pipe? (rebuiltSI)
im not postive but i think that you can get a test pipe if thats what your looking for and get a spacer for the o2 sensor (they are usually called spark plug anti-fouler). it spaces the o2 sensor away from the cat so it still gets a good reading.
but i dont know that much about that particular CEL code
but i dont know that much about that particular CEL code
06-29-2007, 05:30 AM
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Re: (pdiggitydogg)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by pdiggitydogg »</TD></TR><TR><TD CLASS="quote">i can almost guarantee that its the o2 sensor and not the cat thats at fault...
is it a bosch sensor? how old is it?</TD></TR></TABLE>
No idea.. I bought the car like a month ago. I took it to honda for a different problem, but they had a look at it and told me I needed a new cat. Whether or not they are telling the truth i really dont know. But i guess Ill replace the secondary O2 first and see what happens.
is it a bosch sensor? how old is it?</TD></TR></TABLE>
No idea.. I bought the car like a month ago. I took it to honda for a different problem, but they had a look at it and told me I needed a new cat. Whether or not they are telling the truth i really dont know. But i guess Ill replace the secondary O2 first and see what happens.
06-29-2007, 05:42 AM
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Re: P0420 cat problem- test pipe? (electron_si)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by electron_si »</TD></TR><TR><TD CLASS="quote">im not postive but i think that you can get a test pipe if thats what your looking for and get a spacer for the o2 sensor (they are usually called spark plug anti-fouler). it spaces the o2 sensor away from the cat so it still gets a good reading.
but i dont know that much about that particular CEL code</TD></TR></TABLE>
Yes, BLOX makes an extra screw-in bung, that goes in the existing bung for the secondary 02 sensor, placing it farther from the exhaust flow, confusing it into thinking its reading for less emmisions, therefore eliminating the CEL you get for removing your cat. Its available on Inline4.com for like $5 a piece.
But keep in mind it may be the sensor itself, make sure it isnt broken.
but i dont know that much about that particular CEL code</TD></TR></TABLE>
Yes, BLOX makes an extra screw-in bung, that goes in the existing bung for the secondary 02 sensor, placing it farther from the exhaust flow, confusing it into thinking its reading for less emmisions, therefore eliminating the CEL you get for removing your cat. Its available on Inline4.com for like $5 a piece.
But keep in mind it may be the sensor itself, make sure it isnt broken.
06-29-2007, 05:47 AM
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Re: P0420 cat problem- test pipe? (rebuiltSI)
It works like this.
There is an o2 before your cat and after. Very simple.
The front o2 switches lean to rich pretty quickly. If you graphed it out on a waveform scanner it looks like a radio frequency wave. Just emagine a normal waveform with peaks and valeys.
Now that's what the front o2 looks like. After the Cat cleans the exhaust, the REAR o2 reads more like a line, a strait line. If the REAR o2 waive starts to MIRRIOR the front, then it means the cat is not working, and thus the code.
Sometimes a slow or faulty FRONT o2 can cause this code, sometimes a faulty REAR o2 can cause this code, but many times the cat is not working like it should.
If you install a test pipe, you will ALWAYS have this code as the front and rear o2 will obviously read the same and the ECU will see there is a problem. A simulator will fix it with the test pipe.
You can have it PROPERLY diagnosed at a shop that has the know how and equipment, or you can start waisting your money and throw parts at it. A good diagnosis runs about the same as an o2. Personally, I'd have it diagnosed first, but not all shops are good at that.
There is an o2 before your cat and after. Very simple.
The front o2 switches lean to rich pretty quickly. If you graphed it out on a waveform scanner it looks like a radio frequency wave. Just emagine a normal waveform with peaks and valeys.
Now that's what the front o2 looks like. After the Cat cleans the exhaust, the REAR o2 reads more like a line, a strait line. If the REAR o2 waive starts to MIRRIOR the front, then it means the cat is not working, and thus the code.
Sometimes a slow or faulty FRONT o2 can cause this code, sometimes a faulty REAR o2 can cause this code, but many times the cat is not working like it should.
If you install a test pipe, you will ALWAYS have this code as the front and rear o2 will obviously read the same and the ECU will see there is a problem. A simulator will fix it with the test pipe.
You can have it PROPERLY diagnosed at a shop that has the know how and equipment, or you can start waisting your money and throw parts at it. A good diagnosis runs about the same as an o2. Personally, I'd have it diagnosed first, but not all shops are good at that.
06-29-2007, 05:56 AM
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Re: P0420 cat problem- test pipe? (juevi)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by juevi »</TD></TR><TR><TD CLASS="quote">It works like this.
There is an o2 before your cat and after. Very simple.
The front o2 switches lean to rich pretty quickly. If you graphed it out on a waveform scanner it looks like a radio frequency wave. Just emagine a normal waveform with peaks and valeys.
Now that's what the front o2 looks like. After the Cat cleans the exhaust, the REAR o2 reads more like a line, a strait line. If the REAR o2 waive starts to MIRRIOR the front, then it means the cat is not working, and thus the code.
Sometimes a slow or faulty FRONT o2 can cause this code, sometimes a faulty REAR o2 can cause this code, but many times the cat is not working like it should.
If you install a test pipe, you will ALWAYS have this code as the front and rear o2 will obviously read the same and the ECU will see there is a problem. A simulator will fix it with the test pipe.
You can have it PROPERLY diagnosed at a shop that has the know how and equipment, or you can start waisting your money and throw parts at it. A good diagnosis runs about the same as an o2. Personally, I'd have it diagnosed first, but not all shops are good at that.</TD></TR></TABLE>
Now thats a helpful answer!.. anyways I have a good relationship with this shop because they just put a new motor in for me, so he puts me in top priority
. He might not charge me anything to diagnose it so I shall be taking it there soon. thanks guys
There is an o2 before your cat and after. Very simple.
The front o2 switches lean to rich pretty quickly. If you graphed it out on a waveform scanner it looks like a radio frequency wave. Just emagine a normal waveform with peaks and valeys.
Now that's what the front o2 looks like. After the Cat cleans the exhaust, the REAR o2 reads more like a line, a strait line. If the REAR o2 waive starts to MIRRIOR the front, then it means the cat is not working, and thus the code.
Sometimes a slow or faulty FRONT o2 can cause this code, sometimes a faulty REAR o2 can cause this code, but many times the cat is not working like it should.
If you install a test pipe, you will ALWAYS have this code as the front and rear o2 will obviously read the same and the ECU will see there is a problem. A simulator will fix it with the test pipe.
You can have it PROPERLY diagnosed at a shop that has the know how and equipment, or you can start waisting your money and throw parts at it. A good diagnosis runs about the same as an o2. Personally, I'd have it diagnosed first, but not all shops are good at that.</TD></TR></TABLE>
Now thats a helpful answer!.. anyways I have a good relationship with this shop because they just put a new motor in for me, so he puts me in top priority
. He might not charge me anything to diagnose it so I shall be taking it there soon. thanks guys
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