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Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by Paul Howd <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5151' width='330' height='300' border=0 style='border:none;'> on November 29, 2008, 4:33 pm
Paul Howd

Customer has just had complete exhaust system replaced by Kwik-fit (including cats, but not including the fore and aft Lambda sensors)

After a couple of days the MIL came on. On scanning I got "Cat efficency bank 2".

Now, I also found a small exhaust leak up by the manifolds and have advised him to go back to get this sorted before going any further with diagnostics.

(I Hope it is not the head to manifold gaskets! Other wise the poor chap will discover the true meaning of the word "Pain!")

Fore sensors seem to be switching correctly and at a good rate. Aft sensors are both at 0.46 volt with only small variation on blip and overun.

I am hoping that sealing the exhaust leak will solve the problem but if it doesnt how can I confirm whether or not the fault lies with the non-oem cats.

Its an expensive thing to have to recommend without having some way of knowing for sure, especially since doing so will result in agro with kwik-fit over the suitability of aftermarket cats! (I have already pointed out that it is normal good practace to replace sensors with a new cat, but since they seem to be working OK and cat failure was not the reason for replacement it doesnt seem strictly necesarry, especially since it would be another £400 or so)

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by David Davies <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5218' width='330' height='300' border=0 style='border:none;'> on November 29, 2008, 4:44 pm, in reply to "Vauxhall Omega V6 "Cat efficiency" 02 plate"
David Davies

I should think they are quite used to disputes about quality of aftermarket cats! Anyway to confirm operation of cat the obvious thing would be to evaluate all 4 gas readings and lambda value.Can you post them?

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by Paul Howd <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5151' width='330' height='300' border=0 style='border:none;'> on November 29, 2008, 5:18 pm, in reply to "Re: Vauxhall Omega V6 "Cat efficiency" 02 plate"
Paul Howd

As I said, I am waiting for him to get the leaks sorted before doing anything else.

When he gets back to me I will try out my new NOX-BOX on it and let you know!(which allows me to take gas readings during a test drive as well as when stationary)

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by Mark Banks <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1138' width='330' height='300' border=0 style='border:none;'> on November 29, 2008, 10:16 pm, in reply to "Re: Vauxhall Omega V6 "Cat efficiency" 02 plate"

Hi Paul,

I had to sort some issues with a 3.2 one of these earlier this year after it had an auto gear box fitted at a main dealer.

It was also reporting a cat efficiency code a few days later but on bank 1, I dont know if yours is the same but I was concerned because the post cat lambda sensors were positioned in between the pre cat and main cat on the down pipe. I had found some info on the omega owners forum about this fault and it was suggested that threaded bosses be welded in to the down pipe after the main cat and the post cat sensors be moved down the line and the original holes plugged.

Anyway, fortunatley before getting carried away i checked the wiring against a diagram and found that the pre and post cat sensors had been incorrectly plugged in to the loom (reversed), the multi plugs are the same.

Might be worth a look incase kwik fit got it wrong (as if!)

Hope this helps, regards

Mark

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by Paul Howd <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5151' width='330' height='300' border=0 style='border:none;'> on November 29, 2008, 10:36 pm, in reply to "Re: Vauxhall Omega V6 "Cat efficiency" 02 plate"
Paul Howd

The "Live data" sugests that the fore and aft sensors are functioning correctly.

I am guessing (hoping) that air leaks in the exhaust up near the manifold are causing incorrect readings which the ECU is interpreting as poor cat efficiency.

I cannot do any more untill the vehicle comes back from KF.

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by Matt Elliott <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1416' width='330' height='300' border=0 style='border:none;'> on November 30, 2008, 12:36 am, in reply to "Re: Vauxhall Omega V6 "Cat efficiency" 02 plate"
Mattew Elliott

I'm putting money on the fault being an aftermarket cat , we see it all the time , I bet there was nothing wrong with the old cats ,We had a corrolla once & kwik fit fitted a new cat anyway long story short they ended up buying customer an oe one at great expense, I'm shocked at the amount of cat's they replace I would say 90% of my customers that have been there for an exhaust they've tried selling them whole system including cat I think watchdog should get involved I reckon I could give examples all night of fast fit incidents.

Just make sure when you find out it is the cat that the customer get's an oe fitted foc as I seriously doubt there would of been anything wrong with old one I normally write a report out explaining why only oe cat's should be fitted to cars with a post cat sensor that normally does the trick.

sorry for the rant

Matt

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by Paul Howd <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5151' width='330' height='300' border=0 style='border:none;'> on November 30, 2008, 1:03 am, in reply to "Re: Vauxhall Omega V6 "Cat efficiency" 02 plate"

I have a nasty feeling that you may be right (as I have already explained to the customer-who is an electronics engineer, so actually understood what I was talking about!)

I still live in hope that sorting the exhaust leak will fix the problem, but I am not holding my breath!

The cats were (aledgedly) changed because the exhaust was in rotten corroded condition and replacing the back box ended up requiring everything else being replaced too! (yes, erm...)

I never saw the exhaust before it was changed so I really dont know...

PS I just have the horrible feeling that this is going to end up as one of those "Piggy in the Middle" situations where it is going to end up as being "My" responsibility to negotiate between pissed off customer and reluctant KW, and if it doesnt put the light out it will be "my" fault! and even if everything works out fine I will never be able to charge enough to cover the amount of hassle! (a bit lke dealing with those dreadfull "mechanical break down insurance" companies!)

(Actually, I think the customer realises "exactly" how dificult this sort of fault is to deal with, so it might not be quite that bad! )

Sorry its late and I am a bit, You know!

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by Tony Sefton <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5581' width='330' height='300' border=0 style='border:none;'> on November 30, 2008, 5:17 pm, in reply to "Re: Vauxhall Omega V6 "Cat efficiency" 02 plate"
Tony Sefton

>>>>>>>cat failure was not the reason for replacement<<<<<

That says it all doesn't it. ?? Its either the cats or something that was done at that time, ( sensors plugged into wrong sockets as suggested )

Best thing is to leave the problem with Quick fit, Well they have got all the Top class Diagnostic equipment now haven't they.

Tony.

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by paul whatmough <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT1290' width='330' height='300' border=0 style='border:none;'> on November 30, 2008, 5:43 pm, in reply to "Re: Vauxhall Omega V6 "Cat efficiency" 02 plate"
Paul Whatmough

I read somewhere recently that the rules on after-market cats will change in 2009. All cats sold after a certain date have to made to original manufacturers specification. No more cheap and nasty cats.
Paul...

Re: Vauxhall Omega V6 "Cat efficiency" 02 plate

Posted by Gwyn Williams <iframe src='https://members5.boardhost.com/ukautotalk4/info/user=UKAT5354' width='330' height='300' border=0 style='border:none;'> on November 30, 2008, 9:15 pm, in reply to "Re: Vauxhall Omega V6 "Cat efficiency" 02 plate"
Gwyn Williams

Paul, you are getting too involved with this!! You have found what the problem is, let the customer take it back and let him complain (bitterly!!) to Kwik Fit. It's their problem, they made the profit and caused the problem, let them fix it. Just make sure you get paid! As Tony said, they have all the top notch gear to sort the problem, pity they haven't got top notch cats!! Regards, Gwyn

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