P0420 cheep fix ? Hmmm?
#61
#62
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The best rated Jag mechanic on the Space Coast FL told me on the first week owning my car that I had a bad downstream O2 bank one after his test and was the cause of the P0420 so I changed that a while back. He wanted almost $300 for that alone. Since then I've been trying to understand this. I bought the iCarsoft OBD that tests everything on data stream. These were taken at idle with engine coolant temp @ 86-90c (186-194F) at idle.
O2 output bank 1s2 = 0.520-0.570 (P0420 code) new sensor
O2 output bank 2s2 = 0.210-0.675
o2 sensor current bank 1&2 was 0 uA -23.9 uA jumping around and I have no idea what "uA" is or what that means.
Long term fuel trims warmed to @ 86c = 3.9% bank 1 and 2.3% bank 2
A little later @ 90c = 5.5% bank 1 and 3.9% bank 2
O2 output bank 1s2 = 0.520-0.570 (P0420 code) new sensor
O2 output bank 2s2 = 0.210-0.675
o2 sensor current bank 1&2 was 0 uA -23.9 uA jumping around and I have no idea what "uA" is or what that means.
Long term fuel trims warmed to @ 86c = 3.9% bank 1 and 2.3% bank 2
A little later @ 90c = 5.5% bank 1 and 3.9% bank 2
Last edited by ZenFly; 11-09-2015 at 05:01 AM.
#63
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u = micro, though m for milli is perhaps more common here
Obviously you expect banks to be similar side-to-side for the sensor outputs, but your downstreams aren't (thus the code).
If it was the right sensor then you seem to be saying it's flatlined and I suppose that would be a bad cat or some other fault (nothing else springs to mind).
Obviously you expect banks to be similar side-to-side for the sensor outputs, but your downstreams aren't (thus the code).
If it was the right sensor then you seem to be saying it's flatlined and I suppose that would be a bad cat or some other fault (nothing else springs to mind).
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ZenFly (11-09-2015)
#64
![Default](/forum/images/icons/icon1.gif)
u = micro, though m for milli is perhaps more common here
Obviously you expect banks to be similar side-to-side for the sensor outputs, but your downstreams aren't (thus the code).
If it was the right sensor then you seem to be saying it's flatlined and I suppose that would be a bad cat or some other fault (nothing else springs to mind).
Obviously you expect banks to be similar side-to-side for the sensor outputs, but your downstreams aren't (thus the code).
If it was the right sensor then you seem to be saying it's flatlined and I suppose that would be a bad cat or some other fault (nothing else springs to mind).
#65
#66
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Today I just need to learn what all those dancing numbers mean on my data stream and their relation to each other. Without that I'm in the dark so I have been reading up on it but different places explain it in various ways and all seem kind of vague to the old guy here..
#67
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ZenFly (11-09-2015)
#68
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The EEC systems were quite different from the later OBD2 stuff. I miss playing with them, but diagnostics took longer. Fault codes didn't point to the problem as well as with OBD2, even tho it still doesn't always point to the right component. Pretty sure Ford didn't use widebands back then even tho they existed. I don't know who was first to use them but I recall Cadillac as my first experience with them.
It's kinda odd that part of the reason for widebands is to eliminate the switching, yet here we have a car apparently using the downstreams because of switching. Technology I guess, always improving accuracy with every new breakthrough.
My basic understanding of the widebands: They have a reference input signal and they output an amperage signal to the computer based on how much above or below the reference signal they are generating. So if they're generating the same as the reference its output would be 0. In some cases the computer converts this amperage signal to voltage for you to see with your scanner. The Jag gives you the amperage as witnessed by your milliamp readings. I haven't played with them much so I'm sure google will have better information for you.
It's kinda odd that part of the reason for widebands is to eliminate the switching, yet here we have a car apparently using the downstreams because of switching. Technology I guess, always improving accuracy with every new breakthrough.
My basic understanding of the widebands: They have a reference input signal and they output an amperage signal to the computer based on how much above or below the reference signal they are generating. So if they're generating the same as the reference its output would be 0. In some cases the computer converts this amperage signal to voltage for you to see with your scanner. The Jag gives you the amperage as witnessed by your milliamp readings. I haven't played with them much so I'm sure google will have better information for you.
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ZenFly (11-09-2015)
#69
The following users liked this post:
ZenFly (11-09-2015)
#70
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The EEC systems were quite different from the later OBD2 stuff. I miss playing with them, but diagnostics took longer. Fault codes didn't point to the problem as well as with OBD2, even tho it still doesn't always point to the right component. Pretty sure Ford didn't use widebands back then even tho they existed. I don't know who was first to use them but I recall Cadillac as my first experience with them.
It's kinda odd that part of the reason for widebands is to eliminate the switching, yet here we have a car apparently using the downstreams because of switching. Technology I guess, always improving accuracy with every new breakthrough.
My basic understanding of the widebands: They have a reference input signal and they output an amperage signal to the computer based on how much above or below the reference signal they are generating. So if they're generating the same as the reference its output would be 0. In some cases the computer converts this amperage signal to voltage for you to see with your scanner. The Jag gives you the amperage as witnessed by your milliamp readings. I haven't played with them much so I'm sure google will have better information for you.
It's kinda odd that part of the reason for widebands is to eliminate the switching, yet here we have a car apparently using the downstreams because of switching. Technology I guess, always improving accuracy with every new breakthrough.
My basic understanding of the widebands: They have a reference input signal and they output an amperage signal to the computer based on how much above or below the reference signal they are generating. So if they're generating the same as the reference its output would be 0. In some cases the computer converts this amperage signal to voltage for you to see with your scanner. The Jag gives you the amperage as witnessed by your milliamp readings. I haven't played with them much so I'm sure google will have better information for you.
#71
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If you want more detail from this site see https://www.jaguarforums.com/forum/s...-149649/page2/
They're basically Steve's (xjrguy) posts about trims (General Tech forum?)
They're basically Steve's (xjrguy) posts about trims (General Tech forum?)
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ZenFly (11-09-2015)
#72
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If you want more detail from this site see https://www.jaguarforums.com/forum/s...-149649/page2/
They're basically Steve's (xjrguy) posts about trims (General Tech forum?)
They're basically Steve's (xjrguy) posts about trims (General Tech forum?)
I also am going to try a can of that BG44K as was discussed there.
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