That time of year again... Failed for the 2nd year Iv'e had it !

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Mark-RS
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That time of year again... Failed for the 2nd year Iv'e had it !

Post by Mark-RS » Wed Jan 30, 2019 1:09 pm

But not as substantial as the last time :D

M.O.T day gives me the following...

Headlight level is low.

Rear pads, which I knew were getting low anyway.

And Emmisions ! Which has suprised me !

Only failed on the Lambda readings, which judging by the paperwork should be between 0.97 and 1.03. Mine reads 1.16

They didn't really have a clue what the issue was but said, maybe exhaust leak, which they didn't find on inspection, air leak or sensor issue ?

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Mark-RS » Thu Jan 31, 2019 11:34 am

So any advice on things I can get the garage to look at for this Lambda reading ?

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simonpoulton
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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by simonpoulton » Thu Jan 31, 2019 12:18 pm

Check your OE exhaust (if you still have it) around the welds on the resonators. Mine had cracked and was giving high lamda readings. Replaced with Milltek naturally...
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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Ajc » Thu Jan 31, 2019 12:22 pm

Could also be a cat on it's way out . Did he check the reading on both tips or just the one ?
Cheers Al

04 c5 rs6 , Ebony Black, Bare shell repaint , Milltek's, PSS9's,Hotchkis Arb's,Gutted precats, hybrid turbos, Bosch 044 ,And an annoying EML light

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Mark-RS » Thu Jan 31, 2019 1:21 pm

Only checked on one tip. Passenger side.

Left it running at about 4krpm for about 10 mins which I though a bit much...

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Daveperc
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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Daveperc » Thu Jan 31, 2019 2:54 pm

The hotter the better to get low readings.

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by R56WUF » Thu Jan 31, 2019 3:27 pm

My previous RS6 failed on the emissions test at Dundee Audi. I went and drove the car for about 1/2 mile with the car in second gear at approximately 60mph, took it straight back and the tester hooked it up and it passed. Always worth giving the system a wee blast.
2004 C5 RS6 - Missano Red (the fastest colour...) - Departed
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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Mark-RS » Thu Jan 31, 2019 7:07 pm

I did take it for a run before going there, but due to it being -2 I couldn't really give it any stick :-(

I really hope it's not the Cat... Don't see why it would be ? They don't go very often do they ?

I'm hopeful a service and a good check for leaks in the system should cure things :-)

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by PipRS6 » Fri Feb 01, 2019 9:44 am

Yup, cats don't work unless they're warm. That's the point of the pre-cats. Closer to the engine they warm up quicker. Give it a good thrashing then ask the tested to do emissions first.

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Shoppinit » Fri Feb 01, 2019 10:14 am

What do the car's lambda probes read? If they are not complaining and the car is failing emissions then it seems likely that one or both have failed.
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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Ajc » Fri Feb 01, 2019 11:07 am

Lambda reads air fuel mixture , they had a certain amount of tolerance , however I think the car uses a mixture of lambda and egt top work out how it needs too tweek it's running. In the turning world egt a bit more too . On the car the pre and post lambda is checks and altered , though I think the pre is more for the sia side and pre heating the first cat . I service and fresh filters can go a way too changing lambda reading though , so may be worth trying it if you've not already
Cheers Al

04 c5 rs6 , Ebony Black, Bare shell repaint , Milltek's, PSS9's,Hotchkis Arb's,Gutted precats, hybrid turbos, Bosch 044 ,And an annoying EML light

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Ben_r1 » Fri Feb 01, 2019 4:32 pm

Doesn’t a failing cat usually give an eggy smell? But yes let’s hope it isn’t that, I’m betting it’s another ‘engine out job’.

A friendlier mot tester could be the easiest solution here :sekret:

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Ajc » Fri Feb 01, 2019 6:09 pm

It is possible too get the cats out without dropping the engine , but it does still involve dropping the back end of the sub frame down and a really long extension bar .
Mine is soon too have no cats at all , so I wont have to worry . I work at a place that does mot's now :thumbs:
Cheers Al

04 c5 rs6 , Ebony Black, Bare shell repaint , Milltek's, PSS9's,Hotchkis Arb's,Gutted precats, hybrid turbos, Bosch 044 ,And an annoying EML light

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Ben_r1 » Mon Feb 11, 2019 11:26 am

Ajc wrote:
Fri Feb 01, 2019 6:09 pm
It is possible too get the cats out without dropping the engine , but it does still involve dropping the back end of the sub frame down and a really long extension bar .
Mine is soon too have no cats at all , so I wont have to worry . I work at a place that does mot's now :thumbs:
I was quoted for an engine out job to fit a pair of decats on mine as the specialist was adamant it’s near impossible to remove the bolts without the studs snapping.

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Re: That time of year again... Failed for the 2nd year Iv'e had it !

Post by Mark-RS » Mon Feb 11, 2019 7:27 pm

Oil change and Plug change and the readings are now within normal levels.

Back in tomorrow for the retest.

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