W211 OM642 decat information

h4r7l3

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I a om642 3.0 v6 and want to do a decat, I only have a oxygen sensor and temperature sensor after the cat, do I need to code anything out or just run it as normal no issues after decatting?
 

LostKiwi

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Why do you want to do a decat? Modern cats have very little resistance to flow and you'll set yourself up for an MOT failure in the near future.
 

matthew k

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Why do you want to do a decat? Modern cats have very little resistance to flow and you'll set yourself up for an MOT failure in the near future.
Plus it will stink and pollute the environment, and as the engine is set up to work with one may not be as beneficial as you expect.
 
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h4r7l3

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I've been looking at YouTube and seeing the decat done on the straight sixs and some on om642 but no information about the oxygen sensor and temperature sensor just after the cat. I would open up the cat and put a pipe in place
 

LostKiwi

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You do realise that it's illegal to disable emissions control devices?
 
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h4r7l3

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I have a spare catalyct converter as mine is just a bolt on and off, I just want to know about if any errors will come up. Im going to be de-cat pipe within the cat and then adding a 90 degree spacer for the oxygen sensor.

I am not asking about rules and regulations, im asking due to people already doing this previously.
 

LostKiwi

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I am not asking about rules and regulations, im asking due to people already doing this previously.
You may not be asking but I am advising you that you will make your car unroadworthy. That will potentially nullify your insurance and frankly we have enough uninsured vehicles out there without you adding yours.
From an ethical perspective we have a responsibility to maintain our vehicles to a standard where they pollute as little as possible. A decat (whether petrol or diesel) shows a blatant disregard for others around you and for our planet.
Don't get me wrong, I'm no eco warrior but I do my bit to make my vehicles as non polluting as possible.

I fail to see what you expect to gain from doing this.
 
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h4r7l3

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It has been done plenty of times and I want a better exhaust note.

As shown below:





Loads of people have done this
 

LostKiwi

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It has been done plenty of times and I want a better exhaust note.

As shown below:





Loads of people have done this

Still doesn't make it legal or make your insurance valid.

None of them is just a cat delete.
The first one is a resonator delete (after the cat).
Second is everything removed.
Third is a DPF delete (which is not a cat).
Fourth is also a cat delete and full system (and FFS he has an AMG badge on the back - to55er).

Instead of fiddling with the cat do it properly and get a custom cat back exhaust. Simply removing the cat will make little difference as it's not a silencer and has minimal restriction to flow.

And you'll never get as nice as sound from a diesel as a petrol..
 
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Capra

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Just buy a petrol AMG, there are enough out there going cheap. That's what I would do if I cared that much about the exhaust note. I know there are some better sounding diesels, but they still sound like a diesel.
 
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h4r7l3

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I have a cat back system ( no silencers or backboxes) already and I then started looking online and seeing about decats to get abit more of a rasp note. cant think of anything else to do to get a better note
 

LostKiwi

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I have a cat back system ( no silencers or backboxes) already and I then started looking online and seeing about decats to get abit more of a rasp note. cant think of anything else to do to get a better note
It's a diesel. It will never rasp like a petrol due to the turbo acting as a silencer and the lack of revs a diesel runs at.
If you want a nice exhaust note you really do need a petrol engine. They rev higher and can produce a much better exhaust note. They also burn fuel differently which also changes the note.
 

Doug1234

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Lostkiwi is correct about turbo acting as a silencer , have a look on Youtube at the various videos of 642’s with straight pipes all they do is make a bit more noise at idle
I thought it would be nice to get a bit more of a v6 burble from my Jeep 3.0crd but nothing can be done.
 

Craiglxviii

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I have a cat back system ( no silencers or backboxes) already and I then started looking online and seeing about decats to get abit more of a rasp note. cant think of anything else to do to get a better note
I can. Buy a V6 or V8 petrol.
 

LostKiwi

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I'll just leave this here for folks to ponder (from the dft website):

Under the Road Vehicles (Construction and Use) Regulations (Regulations 61(7) and 61A(3)) and the Road Traffic Act 1988 (Section 42) it is an offence to use on a road a vehicle which has been modified in such a way that it no longer complies with the air pollutant emissions standards it was designed to meet.

The potential penalties are £1,000 for a car and £2,500 for a van, lorry or bus.

Under the Road Traffic Act 1988 (Section 75) it is an offence to alter a vehicle in such a way that the use of the vehicle on a road would be unlawful. A person altering the vehicle (if they knew or believed that the vehicle would be used on the road) could be found guilty of an offence under the Act.

Potential penalties are unlimited fines.
 

Steve@Avantgarde

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I would speak to Anthoney at GAD tuning.

He can unlock more power and economy with out removing the emissions system. You also open up the possibility of many running issues by just removing the cat.

The older straight 6's had 2 cats on them, and the upper cat can break and block the lower cat. The upper cat could be removed to fix the loss of power fault but the lower cat was kept. This wasn't for performance, but a cost effective fix to a fault.
 

davidsl500

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How about a 1000 Watt amp and external speakers with a close coupled microphone. When you accelerate away, make brum brum noises like a proper V8..... I'll get my coat
 

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How about a 1000 Watt amp and external speakers with a close coupled microphone. When you accelerate away, make brum brum noises like a proper V8..... I'll get my coat
RMS or peak :rolleyes:
 

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