Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: Mr Hagon on 29 May 2009, 21:53:12

Title: Emissions Light and Cats
Post by: Mr Hagon on 29 May 2009, 21:53:12
[size=8]The EML has come on and doing the pedal test has revealed the 0420 and 0430 codes.

I've checked the last MOT from April this year and the results are below.

Fast Idle
CO: 0.01
HC: 6
Lambda: 1.00

Natural Idle
CO: 0.00

Am I looking at new cats as that's going to be astronomical in cost, or could it be something else?  Car drives fine, no loss of power, just the light on the dashboard staring at me!

Mark[/size]
Title: Re: Emissions Light and Cats
Post by: VXL V6 on 29 May 2009, 21:57:46
I presume you aren't talking about your 3.0 Elite?
Title: Re: Emissions Light and Cats
Post by: Mr Hagon on 29 May 2009, 22:04:27
Quote
I presume you aren't talking about your 3.0 Elite?
No, need to update my sig, talking about a 3.2 Elite now...
Title: Re: Emissions Light and Cats
Post by: VXL V6 on 29 May 2009, 22:11:32
Ah right!

OK, just the standard failing precats (there's a good explanation by Kevin Wood in the guides).

Basically the car will still pass it's MOT as the main cats will still be keeping the emissions within MOT emissions spec.

Title: Re: Emissions Light and Cats
Post by: Mr Hagon on 29 May 2009, 22:18:35
Quote
Ah right!

OK, just the standard failing precats (there's a good explanation by Kevin Wood in the guides).

Basically the car will still pass it's MOT as the main cats will still be keeping the emissions within MOT emissions spec.

Ah yes, have just had a good search through and read Kevin's article too.

Sounds a little daft in that the pre-cats fail, emissions light comes on but you won't fail an MOT.

I expect this means a Vx stealer will suggest that you part with loads of money for a pair of new cats.  Do you save much on TC?

Can you turn off the light on the dashboard - expect you need TechII for that or an obliging dealer (who would rather you fixed the problem than ignored it!)?
Title: Re: Emissions Light and Cats
Post by: VXL V6 on 29 May 2009, 22:31:16
Lamp can be reset with any reasonable code reader / resetter but it'll come back on days / weeks / months later with ever increasing regularity.

Best long term answer is to relocate the Lambda's behind the main cat, a few members have done this (Albatross, SP_32 and Mick Dundee) and the ecu is a lot happier (the lamp hasn't lit on any of these cars since)!

Cheapest answer is to remove the bulb.

Expensive answer is to replace the cats but at £711 a side (the price when I enquired in 2007) I don't think anyone will be doing that!
Title: Re: Emissions Light and Cats
Post by: Mr Hagon on 29 May 2009, 22:36:24
Quote
Expensive answer is to replace the cats but at £711 a side (the price when I enquired in 2007) I don't think anyone will be doing that!
Ouch, was that a TC or retail price!  And add labour to fit too!
Title: Re: Emissions Light and Cats
Post by: Kevin Wood on 29 May 2009, 23:58:06
Those emissions test results look spot on. It's not worth changing the cats. If you get fed up with the light, relocate the post-cat lambda snesors to after the main cats (weld a new boss into the exhaust).

Kevin
Title: Re: Emissions Light and Cats
Post by: feeutfo on 30 May 2009, 00:32:29
re Mick Dundees car and its rebuild. I saw that Mark had welded new bosses to move the 2nd lambda into. But was it ever tried with the lambdas in original position? To see if the rebuild(and specifically the new valve stem seals) made the light go out?
Title: Re: Emissions Light and Cats
Post by: VXL V6 on 30 May 2009, 00:41:52
While I can see that the precat can effectively be 'poisoned' by the valve stem seal issue (which was only a small number of engines, not the whole 2.6 - 3.2 production run), I think the main culprit is simply that the precats size is not sufficient to sustain the level of task it needs to perform especially as the efficiency deteriates over time.
Title: Re: Emissions Light and Cats
Post by: feeutfo on 30 May 2009, 01:06:48
i suppose if the cat was contaminated/poisend/damaged whatever, then the code would return.

But if oil burning only was setting the code off...?

I await the arrival of my engine light.... Any day now, probably. Maybe lpg will delay the inevitable?
Or does driving like an idiot help?
Title: Re: Emissions Light and Cats
Post by: Entwood on 31 May 2009, 22:21:45
Quote
i suppose if the cat was contaminated/poisend/damaged whatever, then the code would return.

But if oil burning only was setting the code off...?

I await the arrival of my engine light.... Any day now, probably. Maybe lpg will delay the inevitable?
Or does driving like an idiot help?

I've had just 2 instances of an 0420 in a year since having LPG fitted, last one was back in October.

IMHO doing some decent runs seems to keep the cats clean and the problem is less common. As I use the caravan a lot, the car is used on decent length runs when it is worked fairly hard, I'm guessing this will cause all the cats to get pretty hot .. and it might help ???

The 2 occasions I've had the 0420 have both been after lots of short runs when things haven't got properly hot ...

Just my thoughts, either way ... the box of tricks turned the light off which means it has paid for itself twice over .. :)
Title: Re: Emissions Light and Cats
Post by: MikeDundee on 01 June 2009, 05:08:25
I have a maxscan code reader Mr Hagon, which will reset the EML noticing you are in west London, if you want it reset. But it will come back on again, eventually.
Title: Re: Emissions Light and Cats
Post by: Kevin Wood on 01 June 2009, 12:23:33
FWIW I've had pre-cat issues for about 18 months now. Fitting LPG made no difference whatsoever. My engine burns no oil at all. Level doesn't move between changes @ 5K and I run 5w30 oil in it.

It doesn't get a workout that often, though, TBH. It gets a 20  mile commute with relatively enthusiastic driving (and stuck behind plodders to balance that out) and the occasional longer journey but, even still, not enough to get a 3.2 properly hot and nothing like a regular caravan trip.

Last time I can remember the emissions light remaining off for significant time was the York meet where <ahem> it did get a bit more of a workout, I suppose. :-[

Sounds like I need to make another trip to Stelvio, purely for research purposes? 8-)

Kevin