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E51 The E51 Catalytic Converter Problem

Hello all,

Still waiting for my Elgrand E51 delivery, but have already a question - can anybody relate to the size of the cats? I was thinking of Euro4 200cell metal cat replacement in front + de-core / pipe in rear, but cant find any size on part list or forum. Any product that can be suggested or referred as an example?
 
Hello all,

Still waiting for my Elgrand E51 delivery, but have already a question - can anybody relate to the size of the cats? I was thinking of Euro4 200cell metal cat replacement in front + de-core / pipe in rear, but cant find any size on part list or forum. Any product that can be suggested or referred as an example?
There was another here by @Wolop I think who made his own system.
 
do you have in Finland a company called powerflow exhausts (i think they are world wide) if so they made and fitted my front cat replacement no rear cats and full exhaust system from stainless steel for £1250 (£490 was labour) they used two generic 400 full metal cell cats and copied the rest of the system if you make your own then its your budget/imagination that is the limit
 
That i seen, but i am in Finalnd (customs will be huge) + i had requested a quote already some time ago - no answer + that post really do not provide dimensions on the cats itselfes or brand / model. I have a welder to do the job here but i will have to supply parts myself.
@Elementian said he'd taken some time away from the forum in a recent post, maybe worth reaching out again.
 
There was another here by @Wolop I think who made his own system.
I got elemetian primary cats and decat pipes really nicely made with a very comprehensive fitting kit can highly recommend 😎
 
I got elemetian primary cats and decat pipes really nicely made with a very comprehensive fitting kit can highly recommend 😎
Ah right. I saw those noise valves and assumed it was something you had done.
 
Hello all,

Still waiting for my Elgrand E51 delivery, but have already a question - can anybody relate to the size of the cats? I was thinking of Euro4 200cell metal cat replacement in front + de-core / pipe in rear, but cant find any size on part list or forum. Any product that can be suggested or referred as an example?
My suggestion would be to not decore any of the cats and just get a either elemetian primarys and decats / or just get a full custom exhaust made straight away, with metallic cats if you have a local company.

I sold my original primary cats for £280 if there were 4 (already decored by vineplace) that would have been £560 towards the expense of the full replacement.
 
Ah right. I saw those noise valves and assumed it was something you had done.
Aha yes i have those but after doing them i wouldn't recommend them, it was an itch that needed scratching and im not happy with them...... yet
 
Hello,

Thank you very much for all your answers - i will squeeze the knownledge of them. However none of above answer my original question - what is the ori cats size.
 
ah sorry maybe winchester could answer that he does them all the time
 
I can see from one product specification the following:
Dimensions:
Diameter: 60mm
Length: 260-268mm
Width/Height: 122mm

I just wonder if that will physically fit there, or too big. This is only the cat size, i assume a little can be played on the pipe itself, but not much.
 
Could I have some advice please in regards to this. I checked the Nissan website and found this. I am still unclear as to any action I may need to take?

https://www.Nissan.co.jp/RECALL/IMAGES/pix.gif
recall notification number3225recall start dateSeptember 13, 2013
https://www.Nissan.co.jp/RECALL/IMAGES/pix.gif
The structure, equipment or performance situation and its cause that are found to be in a non-conforming stateDue to improper programming of the engine control computer, the amount of air taken into the engine may be insufficient when the engine is decelerating from high revs and the accelerator is off. Combustion with a catalyst causes the inside of the catalyst to become hot, and the catalyst may be damaged. For this reason, fragments of the damaged catalyst generate abnormal noise, and if the rear catalyst is clogged, acceleration will be poor, and in the worst case, the engine may stall after the engine malfunctions.
Details of improvementAlong with modifying the engine control program to countermeasure specifications, inspect the damaged state of the catalyst, and replace the catalyst (4 pieces) with a new one if there is an abnormality.
 
Could I have some advice please in regards to this. I checked the Nissan website and found this. I am still unclear as to any action I may need to take?

pix.gif
recall notification number3225recall start dateSeptember 13, 2013
pix.gif

The structure, equipment or performance situation and its cause that are found to be in a non-conforming stateDue to improper programming of the engine control computer, the amount of air taken into the engine may be insufficient when the engine is decelerating from high revs and the accelerator is off. Combustion with a catalyst causes the inside of the catalyst to become hot, and the catalyst may be damaged. For this reason, fragments of the damaged catalyst generate abnormal noise, and if the rear catalyst is clogged, acceleration will be poor, and in the worst case, the engine may stall after the engine malfunctions.
Details of improvementAlong with modifying the engine control program to countermeasure specifications, inspect the damaged state of the catalyst, and replace the catalyst (4 pieces) with a new one if there is an abnormality.

Check your rear cats have been emptied bud, theres so much info on this forum.
 
I don't want to leave things to chance with my Elgrand and reading the advice at the start of this thread am going to go with Option 3. - 'a custom made stainless exhaust'.

Sugoi in Southampton recommended a bolt-on kit - but I wasn't sure what they meant by this?

Two questions:

1. Can anyone recommend a relatively cheap place to get the replacement stainless steel exhaust work done? ( I've looked online at Proflow who seem good value - anyone use them?)

2. Do I have to report this to the insurance company as a modification?

There is a lot of info on here but confusing for a newbie!

Thanks for any replies.
 
ok i got mine done by powerflow full stainless thats front cats no rear cats silencer back box and tail end of your choice £1250 with vat this is with £450 labour it passed mot emissions with flying colours and no you wont have to inform the insurance as it is a replacement of a throw away part
 
ok i got mine done by powerflow full stainless thats front cats no rear cats silencer back box and tail end of your choice £1250 with vat this is with £450 labour it passed mot emissions with flying colours and no you wont have to inform the insurance as it is a replacement of a throw away part
Ok thanks for the info.
 
Your right Alan exchange item w

Your right Alan postal exchange probably won't work economically but over the coming months as we have time we are setting up drive in exchange cats along with exchange reconditioned front wishbones and brake calipiers.
This sounds right up my street Steve. I think I’m going to get over to you over the winter months to have all the bushes done (exchange wishbones or however you do it) and also potentially all wheel bearings. I want a SS exhaust too at some point I don’t know if you can help with that?
Stuart.
 
THIS IS NOT FORUM LORE. THIS IS NOT A MYTH. THERE HAVE BEEN MANY DOCUMENTED INCIDENTS WHERE OWNERS HAVE HAD THEIR ENGINE BLOW UP BECAUSE OF THIS ISSUE. YOU HAVE BEEN WARNED.

CHECK OUT THIS THREAD FOR PROOF

LIST OF AFFECTED MEMBERS

The problem

A widely known issue with the Nissan Elgrand E51 is that the rear cats get blocked causing catastrophic
damage to the engine.

The problem starts with the fact that the E51 has a QUAD CAT SYSTEM. This means there is a PRIMARY and a SECONDARY catalytic converter on EACH BANK of the V6 engine.

The PRIMARY cats are the ROOT CAUSE of problem. Through use, after heating up and cooling down, they start to deteriorate. This happens with ANY ceramic catalytic converter when they reach the end of the their life. As the PRIMARY cats starts to break down and fall apart, the debris is pushed back through the exhaust. At this point, they come into contact with the SECONDARY cats, which creates a blockage.

As more and more of the PRIMARY falls apart, the blockage will prevent any exhaust gasses getting out. The exhaust gases (and dust particles) then build up pressure and go to the only place they can, back into the engine. It doesn't take a mechanic to know that if you put exhaust gas mixed with catalytic converter debris back into an engine, it's not going to last long.

So, that covers the problem, what can you do about it?

There are 3 main options.

1/ DECORE the SECONDARY CATS. This is a simple process. You remove the secondary cats, cut an opening in the top, smash the internals out, weld the opening shut again and re-fit them. This removes the point at which the debris from the PRIMARY cats will get stuck creating a blockage. The debris is just pushed out the back of the exhaust. THIS IS NOT A 100% SAFE OPTION. Debris can still trap itself within the primary cat or the mid box of the exhaust. Although removing the rear cars reduces the chances of catastrophic failure exponentially... it will not 100% stop it from happening.

2/ Remove the SECONDARY CATS. Same principle as option 1, but you remove the cats altogether and replace with a straight through pipe. This is more costly than option 1, BUT what it means is that when it comes to MOT time, you still have the cats to fit to the vehicle if there are ever any issues. As with option 1, this is not a 100% failsafe option for the same reason outlined above.

3/ By far the most expensive option, but still an availability if you have the funds to allow it. Replace the WHOLE system (Manifold back) with a custom made stainless exhaust with single stage, high flow metal sports cat. Dig deep for this one, but the noise will be worth it :) - This option will 100% remove the risk of damage caused by the standard catalytic converter failure problem.

REGARDLESS OF WHAT METHOD YOU CHOOSE - YOU MUST CHECK FOR DEBRIS FROM FAILING FRONT CATS AND INSPECT THEM BEFORE YOU MOVE FORWARD. IF THEY HAVE ALREADY STARTED TO DETERIORATE, YOU SHOULD HAVE THE WHOLE SYSTEM REPLACED AND THE ENGINE HEALTH CHECKED BY A PROFESSIONAL.

But what about.......?

You will fail an MOT if you remove the rear cats and the tester knows they should be there. So if you do fit straight through pipes, keep the cats and then you can fit them again at a later date if you need to.
If you go for option 1, make sure the access hole is cut in the top of the cat so that the head shield will cover the weld when it's sealed up again. If the hole is on the bottom, and the tester can see that they have been tampered with, he'll fail it.

Emissions are NOT affected by removal of the secondary cats. They are only part of the system due to the strict "cold starting" emissions policies in Japan. In the UK the emissions test is done on a warm engine, and therefore the secondary cats serve ZERO purpose.

Is this legal?

I don't know what PC Plod can do about you removing/modifying the cats. But, if you tell an MOT tester that you have modified the cats in any way, and it fails, then technically the car is not road worthy. We know this is bollocks. It'll still pass the emissions test, it will still drive perfectly OK, and you have removed the risk of having your engine blow up when belting down the motorway at no more than 70 (of course).

The choice on what you do is up to you. Keep them if you want. But then every time you drive your E51 you will be wondering when the engine is going to blow up. I know from a personal point of view, I'd rather take the risk with the MOT tester than have catastrophic engine failure and a £4500 engine rebuild bill.

I heard about a Recall for this problem!?

The recall has NOTHING to do with this problem. All it will do is prolong the inevitable. The recall was put out to adjust the fuelling. If your car is subject to the recall, the engine map was putting too much fuel into the engine. This meant that excess fuel was getting blown out of the engine following combustion and then igniting in the exhaust system due to the heat. This meant that the exhaust was getting a lot hotter than it should causing premature deterioration of the primary cats.
With the recall in place, the engine will not overfuel... but it does not mean that the primary cats will not start to disintegrate over time.

There have been at least 2 instances that I know of where a car that was NOT on the recall list has had the engine fail because of blocked cats.

Why does this need doing?

Cars built for EU and UK roads are designed with the climate in mind. Therefore, as part of the manufacture process, there are treatments applied to the bare metal to prevent the chassis corroding. JDM cars are NOT done, because the climate in Japan is very different to ours.

The underseal is required to ensure that your car doesn't turn into a pile of rust over the winter. More importantly, because you are doing this AFTERMARKET, it is something that is seen as temporary, not permanent. The products applied will, over time, wear off or get damaged thus leaving untreated metal to come into contact with salt and moisture.

The better the product you use, the longer it's life. There may even be products out there that come with a "life of the car guarantee"... but I'm sure they'll cost more than £400!

With that in mind, discuss the options available with the garage you chose for your underseal and discuss repeat applications and how often they will be required. If they want your continued business, they will offer all options and tailor the service to your requirements and budget.
Very much appreciate this detailed guide to this important issue!
 
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