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Author Topic: Engine mamagment light  (Read 363 times)

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Engine mamagment light
« on: 01 July 2008, 12:53:39 »

Hi, some advice please.

On Saturday I had the engine management light illuminate (one that looks like an engine side view) on my 3.2 Omega Elite. Popped down to the local independent garage who read the error code which was 'catalyst conversion bank 1'. An exhaust gas test showed everything to be working very well (lambda = 1.001, CO2 ~0.04% IIRC). The error message was cleared.

The light re-illuminated Sunday afternoon after driving around central London for hours. Also the lights-on bleeper sounds as if it is ‘strangled’ and I get a strangled buzzing when the ignition is turned off and the key removed (normally no sound at all) – I’m guessing these two things are somehow connected.

The engine management light went out this morning (what does that mean?) I read out the code (thanks to advice from Autobahnstormers): # P0420 Catalyst System Efficiency Below Threshold (Bank 1). It was suggested that there is ‘known problem here’ and you guys may be able to help.

Thanks for your help



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Re: Engine mamagment light
« Reply #1 on: 01 July 2008, 14:10:52 »

Quite a common problem on the 3.2 it seems

 What "seems" to help cure it is a tankful of "better" fuel ... either non-supermarket or the premium fuels like Shell V etc .. don't know why this works but it appears to.

I've never had the problem, but all most 3.2 owners here keep telling me it'll happen sooner or later ( being on LPG I just hope it's later !!)

I'm sure someone with more knowledge than I will pass by and explain properly ... but it is not something to get too worried about I believe.

The odd sounds I cannot help with, sorry .. :(


By the way .. "Hello" and Welcome  :)  :y :y
« Last Edit: 01 July 2008, 14:12:32 by entwood »
V6 Cam locking/setting kit, Maxscan GS500 OBDII code reader/EML resetter available.  


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Re: Engine mamagment light
« Reply #2 on: 01 July 2008, 15:18:44 »

Unfortunately this does appear to be a common problem with the Omega 3.2 V6 engine. I think it's something to do with the pre-cats not being up to the job on the 3.2. Me and several other 3.2 owners on here have the same problem, but the good news is that your cats are probably ok and won't cause any problems with the MOT emmissions test. I've had my EML light reset a few times now but it will always come back on after a while, although sometimes it switches itself off.

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Re: Engine mamagment light
« Reply #3 on: 01 July 2008, 15:30:09 »

Yep, each exhaust has two cats, a small pre cat and then the main cat.

They also have two lambda sensors, one before both cats and one inbetween the two.

The first lambda control the mixture and the second checks the fficiency of the pre-cat.

Trouble is that this second sensor is a bit sensitive and as the pre-cat starts to age a fault is thrown.

The solution is to re-locate the second lambda after the main cat.
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