MK5 Golf GTI
All Things Mk5 => How to Guides / Troubleshooting => Topic started by: xxx_mojo_xxx on June 09, 2012, 03:07:23 pm
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My car is hesitates briefly every now and then, when I have the throttle wide-open accelerating away at "motorway" speeds.
VWR have said that VAGCOM has logged the following error.
Catalyst System Bank 1 - Efficiency below threshold.
Any ideas, what this might be related to? The way the car behaves seems to be something to do with the coil pack or spark plugs...but that's from a someone (i.e. me) who has trouble holding a spanner!
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http://wiki.ross-tech.com/wiki/index.php/16804/P0420/001056
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My car is hesitates briefly every now and then, when I have the throttle wide-open accelerating away at "motorway" speeds.
VWR have said that VAGCOM has logged the following error.
Catalyst System Bank 1 - Efficiency below threshold.
Any ideas, what this might be related to? The way the car behaves seems to be something to do with the coil pack or spark plugs...but that's from a someone (i.e. me) who has trouble holding a spanner!
I have the same issue.. Can't Fathom the fault. What are your mods Mojo? Car type/map/intake/zorst etc
I can't see or hear any leaks or smell exhaust fumes in the cabin indicating any leaks from a possible cracked milltek downpipe :sad1:
Is it possible to test the 02 sensor.. Anyone how to do it with vcds?
Seems very intermittent, flags up maybe once a week? Is yours the same mojo?
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I can reproduce the issue without fail at 120m/ph.
Is the oxygen sensor the one connected to the air filter pipe?
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I can reproduce the issue without fail at 120m/ph.
Is the oxygen sensor the one connected to the air filter pipe?
I think it's the one nearest the rear of the car on the exhaust. Not 100% sure but it's either that or the one on the downpipe just after the turbo. Hopefully someone might know.
I also have a PCV on its way out, whether this is linked to my error, bringing up this code intermittently. :confused:
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I don't have a PCV as I have the BSH blanking plate.
Also, the sensor you mention sounds more like the lambda sensor rather than the oxygen sensor.
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I reckon Lambda sensor and Oxygen senor are the same things :laugh:
and I have the same fault code P0420 too :pomppomp:
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I reckon Lambda sensor and Oxygen senor are the same things :laugh:
and I have the same fault code P0420 too :pomppomp:
Is yours a perminant fault code or intermittent? Do you get any warning lights? Mine doesn't?
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Hi Guys,
I'm getting the exact same error ..
001056 - Catalyst System; Bank 1: Efficiency Below Threshold
P0420 - 002 - Lower Limit Exceeded - Intermittent
I have started to get the error from when I went to stage 2 (Blueflame exhaust). I have since taken my car back to Kwik-Fit and they have confirmed that
there is no air leak in the exhaust system.
Now, i'm relatively certain that it can't be the second lambda (after the cat) as i've only replaced it a few months ago.
The only lambda that I did not replace was the pre-cat lambda, which I am now leaning towards having changed. If it the second lambda that is picking up a bad reading then I may be able to get around it with a lambda spacer.
The weird thing about it is that the problem only appears in the background (no CEL).
I do not think that all of us have bad catalytic convertors!!
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Hi Guys,
I'm getting the exact same error ..
001056 - Catalyst System; Bank 1: Efficiency Below Threshold
P0420 - 002 - Lower Limit Exceeded - Intermittent
I have started to get the error from when I went to stage 2 (Blueflame exhaust). I have since taken my car back to Kwik-Fit and they have confirmed that
there is no air leak in the system.
Now, i'm relatively certain that it can't be the second lambda (after the cat) as i've only had that replaced a few months ago.
The only lambda that I did not replwas was the pre-cat lambda, which I am now leaning towards having changed.
The weird thing about it is that the problem only appears in the background (no CEL).
Ditto, also cant be a bad cat, or it would be a perminant error surely. Pre cat lambda? Top of the Downpipe?
I'm sure it's a sensor issue as its intermittent. I've removed my remap to see if it happens, and it still does, whether it's because it's a different cell cat to the oem version?
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I was talking to a chap at AMD Technik the other day and he thinks that I may be experiencing the issue due to having a 100 cell cat.
He reckons if I had gone with a 200 cell cat I may have been fortunate enough not to have encountered the issue.
The cat appears to be heating up correctly at a temperature of about 580 degrees. The sensors i'm not sure why they are giving inconsistent readings.
The car basically has two lambda sensors, one before the cat and another after the cat. I think the one that you refer to is the second lambda (downpipe).
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I reckon Lambda sensor and Oxygen senor are the same things :laugh:
and I have the same fault code P0420 too :pomppomp:
Is yours a perminant fault code or intermittent? Do you get any warning lights? Mine doesn't?
No warning lights. Happens intermittently
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I reckon Lambda sensor and Oxygen senor are the same things :laugh:
and I have the same fault code P0420 too :pomppomp:
Is yours a perminant fault code or intermittent? Do you get any warning lights? Mine doesn't?
No warning lights. Happens intermittently
Are u running a stock exhaust?
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I reckon Lambda sensor and Oxygen senor are the same things :laugh:
and I have the same fault code P0420 too :pomppomp:
Is yours a perminant fault code or intermittent? Do you get any warning lights? Mine doesn't?
No warning lights. Happens intermittently
Are u running a stock exhaust?
Nope, Milltek turbo back exhaust
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I reckon Lambda sensor and Oxygen senor are the same things :laugh:
and I have the same fault code P0420 too :pomppomp:
Is yours a perminant fault code or intermittent? Do you get any warning lights? Mine doesn't?
No warning lights. Happens intermittently
Are u running a stock exhaust?
Nope, Milltek turbo back exhaust
Is everyone with this error also run a turbo back system???
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I reckon Lambda sensor and Oxygen senor are the same things :laugh:
and I have the same fault code P0420 too :pomppomp:
Is yours a perminant fault code or intermittent? Do you get any warning lights? Mine doesn't?
yes ,warning light on and a running a stock exhaust system also just passed both the MOT emission test
and VCDS readiness test.
http://www.ross-tech.com/vcds/tour/readiness.html
and I believe there's nothing wrong with CAT or two Lambda sensors.
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I think I'm going to replace my coil packs in the first instance to see if that improves matters.
My car has done close to 75k, and they may be one on the way out. I suspect unburnt fuel caused by poor ignition sparks may cause this.
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I think I'm going to replace my coil packs in the first instance to see if that improves matters.
My car has done close to 75k, and they may be one on the way out. I suspect unburnt fuel caused by poor ignition sparks may cause this.
Let us know how u get on. mine were changed as part of the recall about a year ago. No miss-fires logged but could be a possibility. :happy2:
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yeah, please keep updated :P
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yeah, please keep updated :P
Will do...should have a replacement set in the next couple of days.
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Replaced spark plugs, coil packs, and petrol filter. Car appears to be noticeably better and running a lot smoother.
It's too early to say if this has eradicated the issue. Will keep everyone posted.
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Not wanting to tempt fate, but I am glad to report that the issue has been sorted.
Must have been either a faulty spark plug or coil pack. I'm more inclined to say it was the coil packs. Car has been driven over 600 miles since the replacement and its running like a dream. :jumpmove:
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Hi Mojo,
Please can you tell me if you have a lambda spacer in place (post-cat sensor)?
Has you car been flashed to stage 2?
I get the same problem if I remove my lambda spacer. With the lambda spacer the car complains about the B1 S1 reading too rich?
My coil packs were changed under a recall last year and the spark plugs I changed to Denso's.
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Hi Rav,
My car has stage 2 remap. Not sure if my car has a lambda spacer - is there a way I can check? I did have Denso spark plugs originally, the IK24s. I went back to OEM.
Hope this helps.
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What OEM plugs you got?
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I had NGK 8 plugs after some people were raving about having cooler plugs. I reverted back to Bosch oem 7's and no longer suffer with the same warning error as yourself Rav.
Hth
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Thanks SaintSteve, now I'll need to find some cheap!
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What OEM plugs you got?
Standard Bosch ones from the VW dealership.
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Hi Mojo,
The lambda spacer is basically an extension that fits onto the post-cat (after cat) sensor. Lambda spacers can be L-Shaped or a straight fit, some are slightly angled.
It forces the lambda sensor to sit out of the exhaust as opposed to directly in it.
Please can you tell me if you anyone has one of these fitted to the exhaust and has been able to overcome this error?
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Had this problem and ounce I fitted the stealth 42 spacer no more engine light
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I too have a spacer fitted although it is not a 42 design.
Problem is that with the spacer in place I get a bank 1 sensor 1 too
rich error. Which I believe to be the effect of the spacer.
Without the spacer I get the catalyst error.
I don't think that the 42 design would be any better?