dogsbody

dogsbody

Very senior member
I need a new exhaust on my 2000 diesel. Both tail pipes are shot (big holes on top before the back boxes) but I hadn't noticed any excessive noise so I was thinking of losing a few bits and either doing away with the central silencer or those on the tail pipes. Then I thought that I might as well lose the DPF whilst I'm at it.

Firstly has anybody done away with either silencer(s) and what was the result?

Secondly one supplier has offered to re-map the engine in conjunction with the removal of the DPF to, and I quote, "stop your engine smoking".

I'm nervous about anyone re-mapping my engine. Would this be necessary, or even desirable?
 
The remap will make a big difference to the driving experience

But as always there's a drawback... It will Shorten the life if your gearbox !

Oh well,

My td6 runs brilliant with the remap chip plugged in.

Im also considering to de-cat it and remove the dpf as you have suggested
 
dogsbody said:
I need a new exhaust on my 2000 diesel. Both tail pipes are shot (big holes on top before the back boxes) but I hadn't noticed any excessive noise so I was thinking of losing a few bits and either doing away with the central silencer or those on the tail pipes. Then I thought that I might as well lose the DPF whilst I'm at it.

Firstly has anybody done away with either silencer(s) and what was the result?

Secondly one supplier has offered to re-map the engine in conjunction with the removal of the DPF to, and I quote, "stop your engine smoking".

I'm nervous about anyone re-mapping my engine. Would this be necessary, or even desirable?
Click to expand...
IMO removing the DPF will not make your engine smoke, turbo might spin up a bit earlier because of the reduced back pressure though.
personally I wouldn't waste money on a remap. Actually it's not possible to do a remap as there is no means of writing to the memory in the EDC, all that can be done is to replace or piggy back the chip with another that has a different map. Never thought that was a good idea.
 
My DSE came with a receipt from Janspeed indicating it was fitted with a remapped chip....never did look in the box to find out if it was there or not....she did go like a scalded whippet when poked though so maybe there was one....
 
Datatek said:
True but we knew what we were referring to:)
Click to expand...

MOT test manual Reasons for rejection.

1. An exhaust system not adequately supported.



2. A major leak of exhaust gases from any part of the system.


3. A catalytic converter missing where one was fitted as standard



4. A silencer in such condition, or of such a type, that the noise emitted from the vehicle is clearly unreasonably above the level expected from a similar vehicle with a standard silencer in average condition.






5. An exhaust tailpipe positioned so that fumes are likely to enter the driver’s or passenger area.
 
wammers said:
MOT test manual Reasons for rejection.

1. An exhaust system not adequately supported.



2. A major leak of exhaust gases from any part of the system.


3. A catalytic converter missing where one was fitted as standard



4. A silencer in such condition, or of such a type, that the noise emitted from the vehicle is clearly unreasonably above the level expected from a similar vehicle with a standard silencer in average condition.






5. An exhaust tailpipe positioned so that fumes are likely to enter the driver’s or passenger area.
Click to expand...

Yep, same here. Usual trick is to hammer a pipe through the middle:)
 
They put you off there dog didn't they been fitting loud pipes for years on cars and bike , cat what cat noise Decibels of up to 80 never been rejected yet, remember if someone like Janspeed sell you an Exhaust is must be mot complacent or your money back I don't know of one that's been rejected as they are stamped with ec on them :):):) if when the new rules come !
 
defender300td1 said:
They put you off there dog didn't they been fitting loud pipes for years on cars and bike , cat what cat noise Decibels of up to 80 never been rejected yet, remember if someone like Janspeed sell you an Exhaust is must be mot complacent or your money back I don't know of one that's been rejected as they are stamped with ec on them :):):) if when the new rules come !
Click to expand...

Put that through Google translate got, "Language not found". :D:D:D
 
dogsbody said:
I need a new exhaust on my 2000 diesel. Both tail pipes are shot (big holes on top before the back boxes) but I hadn't noticed any excessive noise so I was thinking of losing a few bits and either doing away with the central silencer or those on the tail pipes. Then I thought that I might as well lose the DPF whilst I'm at it.

Firstly has anybody done away with either silencer(s) and what was the result?

Secondly one supplier has offered to re-map the engine in conjunction with the removal of the DPF to, and I quote, "stop your engine smoking".

I'm nervous about anyone re-mapping my engine. Would this be necessary, or even desirable?
Click to expand...

I've removed my cat, never had it remapped although there was already a chip and a k and n filter on it, i don't notice any extra smoke. I am interested in removing either the middle silence or the end 2 but im not sure what this will sound like, my mot is at 4.30 so il find out if a section of pipe is adequate replacement for a cat!
 
That section of the Vosa guidelines "3. A catalytic converter missing where one was fitted as standard"

regarding the cat only relates to petrol ignition cars

Diesels don't require a cat converter to pass the MOT, even if one was fitted as standard
 
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wammers said:
Number 4 is also applicable to throaty after market systems. But seldom enforced.
Click to expand...
Noise it not too much of a problem here, but they look for the CE mark and the homologation number. No CE mark and number and it will fail even if it's as quiet as an electric car:eek:
 
Thanks lads.
Nothing too surprising there. I rather got the impression that I got a standard reply to the "can you remove my cat" question with my name pasted at the top and a price at the bottom. Just for devilment I might ask them how they intend to re-map my ECU. If it's an uprated chip fitted then that might explain their eye-watering quote - £629 + VAT.
They do offer a fake cat to replace mine but that would be another £79 + VAT.

Just in case you're even wondering, no, I don't think I'll be paying £850 to replace my exhaust !!! Especially not when I can get a standard system from the cat back for under £150, before I start haggling.
 
2.0_hippo said:
That section of the Vosa guidelines "3. A catalytic converter missing where one was fitted as standard"

regarding the cat only relates to petrol ignition cars

Diesels don't require a cat converter to pass the MOT, even if one was fitted as standard
Click to expand...

It quite clearly states a reason for fail is absence of a cat IF one was fitted as standard. ALL P38 diesels have a cat fitted as standard. Therefore if there is no cat it should fail. Simple as that.
 
wammers said:
Put that through Google translate got, "Language not found". :D:D:D
Click to expand...

I did mean ce, I thought the noise was allowed at 80 decibles but I've never seen any equipment at a mot station to test this ? As for ce I thought if it was stamped with it it was certified ok I notice now Janspeed are selling cat back exhuast systems they must be Complying to the new rules.
 
wammers said:
It quite clearly states a reason for fail is absence of a cat IF one was fitted as standard. ALL P38 diesels have a cat fitted as standard. Therefore if there is no cat it should fail. Simple as that.
Click to expand...

Read the Vosa website properly.

"On vehicles that qualify for a full cat emissions test, check the presence of the catalytic converter."

Full emmissions test only applies to spark ignition engines (ie petrol engines)

Diesels only need a smoke test

So the "check for cat converter" part of the legislation doesn't apply to Diesel engined cars

:rolleyes:
 
2.0_hippo said:
Read the Vosa website properly.

"On vehicles that qualify for a full cat emissions test, check the presence of the catalytic converter."

Full emmissions test only applies to spark ignition engines (ie petrol engines)

Diesels only need a smoke test

So the "check for cat converter" part of the legislation doesn't apply to Diesel engined cars

:rolleyes:
Click to expand...

The check for cat on petrol engines that qualify for full cat test, is there to cover the jockeys who presented the cars on LPG for emission check, who had decatted their cars. Then can run them on the road on petrol with no cat. That smokes that practice. What part of a reason to fail, "If a cat is not present but was fitted as standard" is hard to grasp. Or does it say somewhere this does not apply to diesel were cats were fitted as standard. Until told different by VOSA if i was still doing tests they would fail.
 
Last edited:
wammers said:
The check for cat on petrol engines that qualify for full cat test, is there to cover the jockeys who presented the cars on LPG for emission check, who had decatted their cars. Then can run them on the road on petrol with no cat. That smokes that practice. What part of a reason to fail, "If a cat is not present but was fitted as standard" is hard to grasp. Or does it say somewhere this does not apply to diesel were cats were fitted as standard. Until told different by VOSA if i was still doing tests they would fail.
Click to expand...


Its a bit of a grey area really,

from Vosa's website it certainly seems to only relate to petrol engined vehicles.

I have also have spoke to a couple of MOT testers who have also confirmed the cat test only applies to petrol cars. so there's not an issue with De-catting a diesel with regards to passing the MOT test.
 
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