I asked for proof as how do i know that you are just posting a sweeping statement. I never said that removing a DPF is illegal but it will cause the car to emit smoke (which with a DPF it doesn't do). If it is the case that post 2008 cars are stopping on the same fast pass level then why do manufacturers bother to fit these expensive, pointless, unreliable items to their cars?

You can't say for sure that a DPF deleted car will pass an MOT test at all but what i can safely say is that a DPF equipped car will pass a smoke test unless there is a serious fault with the DPF.

Personally i can't stand the things, not from my point of view but from what i have read on here and elsewhere they seem to be more trouble than they are worth but they must be there for some reason. :wonder:

I think you're being confused by the fact that there are two smoke levels in play; the MOT permits 1.5 parts per million measurable particulate matter in the exhaust gas at 2500 rpm. The Euro 5 standard, which must be met to sell new cars into any European market (not just the UK) permits 5 milligrams particulate matter per kilometre driven. They're not directly comparable measures, but the Euro 5 measure is stricter, as (for example) doing around 20 mph at 2500 rpm is the same as doing around 70 mph at 2500 rpm for the MOT test, but requires 1/3rd the particulate level in the Euro 5 test.

You don't need a DPF to meet the MOT standard. You do need one to meet Euro 5. You can drive a car that meets the MOT standard but not Euro 5, but you cannot sell a new car that does not meet Euro 5, thus the proliferation of DPFs.

I asked for proof as how do i know that you are just posting a sweeping statement. I never said that removing a DPF is illegal but it will cause the car to emit smoke (which with a DPF it doesn't do). If it is the case that post 2008 cars are stopping on the same fast pass level then why do manufacturers bother to fit these expensive, pointless, unreliable items to their cars?

You can't say for sure that a DPF deleted car will pass an MOT test at all but what i can safely say is that a DPF equipped car will pass a smoke test unless there is a serious fault with the DPF.

Personally i can't stand the things, not from my point of view but from what i have read on here and elsewhere they seem to be more trouble than they are worth but they must be there for some reason. :wonder:

Hi jrw

The illegal reference was to an earlier post so wasn't aimed at you and I did word it carefully in my response referring to your post separately.

As Farnz points out, DPF's are there to enable manufacturers to meet European wide emissions tests. There seems to be equal dislike of them from manufacturer dev engineers too. Ask any Land Rover engineer about DPF and how even a days off-roading will send a Range Rover into the 'red' condition for DPF and you'll see they are frustrated too.

Having said that as DPF's are further developed their use by the majority of people will be ok and will not cause the issues seen in the past. There will always be exceptions and in these cases a viable option would be to remove the DPF.

Out of interest, if the DPF inners are removed like in some vids, and delated using software, and there is no smoke after, but quit a diesel smell from the exhaust tailpipe on idle , what could be wrong and can it be rectified

1 hour ago, skippy41 said:

Out of interest, if the DPF inners are removed like in some vids, and delated using software, and there is no smoke after, but quit a diesel smell from the exhaust tailpipe on idle , what could be wrong and can it be rectified

 

Sounds like DPF management not fully mapped out and it's trying to do an active re-gen on a non existent DPF by injecting diesel on the "exhaust" stroke which would normally fuel the DPF regen. With no DPF this would carry on down the exhaust

Edited 9 March, 20179 yr by bigjohn

So basically what your saying john is, there is or could be a small fuel feeder pipe going to the DPF somehow,  to supply it with a small amount of fuel to help burn off the soot, 

Pretty sure what he meant was that during the exhaust stroke (fourth stroke of the engine) some fuel is injected into the cylinder. With direct injection fuel can be injected even if the intake valve is closed since it bypasses it.

As TLV mentioned There is no seperate pipe to the DPF. It's simply an extra injetion of diesel using the existing direct injectors during a cylinder exhaust stroke thus expelling diesel out through the exhaust valves / exhaust system down to the  DPF.

 

NB This is why you have to keep an eye on sump oil levels - if you keep having failed regens as well as diesel going down the exhaust pipe it can leak past the piston rings/bores (especially on worn engines)   and eventually will dilute/pollute the engine oil. Vauxhall Zafira's were especially prone to this with quite a few engine failures.

So a proper map out should stop this happening ??

17 hours ago, skippy41 said:

So a proper map out should stop this happening ??

 

Yes - if that is the issue 

 

However remember whilst it is not illegal to have a DPF removed, If a car is fitted with a DPF and it is removed, it is illegal to be "driven" on the road.

 

14 hours ago, bigjohn said:

 

Yes - if that is the issue 

 

However remember whilst it is not illegal to have a DPF removed, If a car is fitted with a DPF and it is removed, it is illegal to be "driven" on the road.

 

No its still there, 

3 hours ago, skippy41 said:

No its still there, 

 

On 09/03/2017 at 19:13, skippy41 said:

Out of interest, if the DPF inners are removed like in some vids, and delated using software, and there is no smoke after, but quit a diesel smell from the exhaust tailpipe on idle , what could be wrong and can it be rectified

 

From your posts it sounds like the DPF casing is there but the actual DPF isn't. If you are having issues after a DPF removal, you should go back to the firm who did it.

has anyone replaced their DPF? Looks as though generic ones are about £300 plus vat + fitting