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[olm]

Hello, it seems that the problems do not stop growing. Today I got the error p0430 that seems to be the catalyst, I have looked for information and it seems a recurring fault of this 3.2 engine. The funny thing is that with the ECU 2.6 this error did not appear and the idle was more stable, would it be a failure of the ECU?

[GastronomicKleptomaniac]

Common for the pre cats (smaller cats before the main ones) to bring this code on. Tankful of decent fuel and a good blast sometimes clears it but otherwise its a case of resetting... Or moving the O2 sensors to behind the main cats.

[olm]

Common for the pre cats (smaller cats before the main ones) to bring this code on. Tankful of decent fuel and a good blast sometimes clears it but otherwise its a case of resetting... Or moving the O2 sensors to behind the main cats.

The fact is that just yesterday I gave it a bit of reed since the idle was oscillating, and today when I came to work the fault light appeared. Is idling related to catalysts?

[TheBoy]

Is this a new ECU?  The idling could still be block learns learning.  Shouldn't take many miles for it to learn.

P0430 is unlikely to be related to idle, unless the issues with idle have destroyed the cat.

Get a cheap OBDII reader on it, and look at the LTFT (should be 0%), and the rich/lean status of all 4 lamdas - front ones should be cycling through rich/lean at about once a second, and rear ones constant lean.

Report back

[olm]

Is this a new ECU?  The idling could still be block learns learning.  Shouldn't take many miles for it to learn.

P0430 is unlikely to be related to idle, unless the issues with idle have destroyed the cat.

Get a cheap OBDII reader on it, and look at the LTFT (should be 0%), and the rich/lean status of all 4 lamdas - front ones should be cycling through rich/lean at about once a second, and rear ones constant lean.

Report back

Yes, it is. So I thought, I should learn, so I did a quiet and fast turn, but it was still the same, oscillating slightly something that I did not do with the ECU 2.6 
The STFT settings are correct, the LTFTs somewhat high although if I used GLP they would not go high as if it happened to me before.
To say that the LPG uses it little by way of test, I am circulating with gasoline so that the ECU learns. Of course, the car now responds much better, that's why I was surprised by failure 0430
I have already reset the fault, I will observe the fuel settings as they have been reset as well. I have seen that it seems a common failure, any problem in canceling the second probe? It is usually done when a car is decat

[Doctor Gollum]

It's probably a historic code. 0420/0430 is pretty much guaranteed to come on at some point on the 3.2.

[olm]

It's probably a historic code. 0420/0430 is pretty much guaranteed to come on at some point on the 3.2.

That's good 

[olm]

Is this a new ECU?  The idling could still be block learns learning.  Shouldn't take many miles for it to learn.

P0430 is unlikely to be related to idle, unless the issues with idle have destroyed the cat.

Get a cheap OBDII reader on it, and look at the LTFT (should be 0%), and the rich/lean status of all 4 lamdas - front ones should be cycling through rich/lean at about once a second, and rear ones constant lean.

Report back

Short route by road, LTFT bank 1 = 7.8%, bank 2 = 4%. The STFT fluctuate correctly and the probes were changed a couple of years ago, would they get contaminated with the previous 3.0 engine head gasket failure?

[Doctor Gollum]

Unlikely as the head gaskets generally fail externally. 

[TheBoy]

This car is pure petrol? Not LPG converted?

If so, check for airleaks in the intake, post MAF.  And exhaust blows.  As the LTFT should be around 0%

Reset the LTFT by putting a fault on the car (eg, unplug MAF), run car for a few seconds. Then plug MAF back in and clear the fault codes with a reader.  That will reset trims (and the block learns)

[olm]

This car is pure petrol? Not LPG converted?

If so, check for airleaks in the intake, post MAF.  And exhaust blows.  As the LTFT should be around 0%

Reset the LTFT by putting a fault on the car (eg, unplug MAF), run car for a few seconds. Then plug MAF back in and clear the fault codes with a reader.  That will reset trims (and the block learns)

Yes, it is LPG but I am running on gasoline, I have to recalibrate the LPG but until it goes well I will not
What MAF values ​​are normal for this car? One important thing, the idle is almost perfect with the ECU 2.6, with the 3.2 it is quite unstable, what is happening? It seems surreal to me

[TheBoy]

OK, good to leave LPG out of the equation for now.

So look for airleaks as suggested.

I'm not saying the MAF isn't faulty, but if it was purely MAF, I'd expect both LTFT to be approx the same.  The MAF on a 3.0/3.2 with A/C off is about 12kg/hr

[olm]

OK, good to leave LPG out of the equation for now.

So look for airleaks as suggested.

I'm not saying the MAF isn't faulty, but if it was purely MAF, I'd expect both LTFT to be approx the same.  The MAF on a 3.0/3.2 with A/C off is about 12kg/hr

Hi. the MAF is 4gr/s, which gives a value of 14.4kg / h. Checked vacuum pipes and all new gaskets since the engine was redone.
But I have noticed one thing, STFT of probe 2 always marked n / a%, I thought it was a failure of the app or something, but doing a test with LPG I have seen that it marked 93.7% in bank 1 which is worse. So I think the fault is going to be there, now, probe or cat? Cats often fail?

[TheBoy]

STFT of probe 2 always marked n / a

By Probe 2, do you mean Sensor 2 on each back, ie, post cat?

Your LPG lamda sesnors with be Sensor 1 on each bank.

[olm]

STFT of probe 2 always marked n / a

By Probe 2, do you mean Sensor 2 on each back, ie, post cat?

Your LPG lamda sesnors with be Sensor 1 on each bank.

Yes.
Another question, seeing that the main problem is idling, how is it regulated in these engines? What can I look at that influences?

[TheBoy]

Idling controlled by ecu maps, temp, MAF and lamdas, and the ECU controls the throttle bodies to give the desired rpm.  Obviously, if the car has been messed around with and has non standard components like the incorrect injectors, ECU config, oiled air filters and so on, its going to struggle.


You MAF reading seems a tad high, unless the A/C was on.  Put the car in ECO and see if the MAF is the same.

But as your LTFT are off, that smacks of an airleak somewhere.  Reset the LTFTs, and monitor them,  If they move from 0%, its likely you have an airleak somewhere.

[olm]

Idling controlled by ecu maps, temp, MAF and lamdas, and the ECU controls the throttle bodies to give the desired rpm.  Obviously, if the car has been messed around with and has non standard components like the incorrect injectors, ECU config, oiled air filters and so on, its going to struggle.


You MAF reading seems a tad high, unless the A/C was on.  Put the car in ECO and see if the MAF is the same.

But as your LTFT are off, that smacks of an airleak somewhere.  Reset the LTFTs, and monitor them,  If they move from 0%, its likely you have an airleak somewhere.

The car was in eco.
What I have tried has been to play with the vacuum tubes of the plenum, one of them affects the idle, obstructing the entrance a bit improves a lot. That tube goes to a piece with a connector, right? Is there any scheme to see how it goes and what function does that piece have?

[Doctor Gollum]

There is such an explanation in the FAQ section 

[olm]

There is such an explanation in the FAQ section 

Yes, I already saw it and I used it to fix leaks from the rocker covers being clogged 
But I think I remember that number 3 goes to a part with a connector, what is the air intake for idling, what is that part and where does it go?

[sjc]

Vacuum pipe connection chart is here
https://www.omegaowners.com/forum/index.php?topic=90499.msg1155332#msg1155332

The only vacuum pipe that goes onto the plenum is for the multi-ram valve at the very back.  There is also the vacuum connection to the fuel pressure regulator which is underneath the plenum.

[biggriffin]

Either get the lambda's moved as per the guide,, or fit a pair of 3.0L downpipes with lambda's fitted as per the guide.

[olm]

Either get the lambda's moved as per the guide,, or fit a pair of 3.0L downpipes with lambda's fitted as per the guide.

I had thought about it. Do you notice a gain by eliminating the precat?

[TheBoy]

Either get the lambda's moved as per the guide,, or fit a pair of 3.0L downpipes with lambda's fitted as per the guide.

I had thought about it. Do you notice a gain by eliminating the precat?

There is a marginal improvement by using good 3.0l cats, and they are likely to last longer than the utter junk fitted to 2.6/3.2 cars.

Nobody suggested removing the pre-cats on 2.6/3.2 exhausts, just moving the lamdas

[olm]

Either get the lambda's moved as per the guide,, or fit a pair of 3.0L downpipes with lambda's fitted as per the guide.

I had thought about it. Do you notice a gain by eliminating the precat?

There is a marginal improvement by using good 3.0l cats, and they are likely to last longer than the utter junk fitted to 2.6/3.2 cars.

Nobody suggested removing the pre-cats on 2.6/3.2 exhausts, just moving the lamdas

Biggriffin has commented to install downpipes 3.0, since we are at work..

[TheBoy]

Either get the lambda's moved as per the guide,, or fit a pair of 3.0L downpipes with lambda's fitted as per the guide.

I had thought about it. Do you notice a gain by eliminating the precat?

There is a marginal improvement by using good 3.0l cats, and they are likely to last longer than the utter junk fitted to 2.6/3.2 cars.

Nobody suggested removing the pre-cats on 2.6/3.2 exhausts, just moving the lamdas

Biggriffin has commented to install downpipes 3.0, since we are at work..

Yes, it does give a marginal improvement, so worth doing.

They need minor mods to make them fit, from memory a few mm have to come off the manifold end, and obviously they need a lamda boss welded in post cat (which you would have to do on your 3.2 cats anyway, due to the failing starting cats).

[biggriffin]

Either get the lambda's moved as per the guide,, or fit a pair of 3.0L downpipes with lambda's fitted as per the guide.

I had thought about it. Do you notice a gain by eliminating the precat?

There is a marginal improvement by using good 3.0l cats, and they are likely to last longer than the utter junk fitted to 2.6/3.2 cars.

Nobody suggested removing the pre-cats on 2.6/3.2 exhausts, just moving the lamdas

Biggriffin has commented to install downpipes 3.0, since we are at work..

Yes, it does give a marginal improvement, so worth doing.

They need minor mods to make them fit, from memory a few mm have to come off the manifold end, and obviously they need a lamda boss welded in post cat (which you would have to do on your 3.2 cats anyway, due to the failing starting cats).

 Correct, grind about 2mm off the protruding bit from manifold end of down pipe,,, the improvements to performance aren't noticeable when driving, if there are any,

[TheBoy]

the improvements to performance aren't noticeable when driving, if there are any,

In my experience, it was slightly noticeable.  That said, the old cats were shagged, which might have been slightly degrading performance.