Peugeot 406 emission problem

[keppler]

Hi all,
My 2.0 hdi had an epic fail on the emissions test at the centre today. It returned a reading of 5.78/m on the smoke test when the limit was 3.0/m.
My egr is has the vacuum pipe disconnected because the control solenoid was broken and sending a constant vacuum to the egr, so it should be in the closed position permanently. The tester noticed this and told me that that could be the issue.
Has anybody here blanked off their egr and then had high emission readings?
Im beginning to get worried about this, the car is pulling very well and its getting between 57-65 mpg on medium to long distance runs so it would be a shame to have to scrap it.
Anybody got any thoughts on this?

[gumby6371]

A closed off egr will theoretically increase emissions but that sounds a lot so I doubt that is the only problem, mixed thoughts on here as regards wonder egr cleaners.
Pulling well and good fuel economy tends to say your injectors are in decent shape but I'd try a good shot of fuel cleaner and an italian tune up and see if it makes a difference, maybe a new set of filters while you're at it.
Make sure everything is nicely up to temperature when he does the test.

[keppler]

A closed off egr will theoretically increase emissions but that sounds a lot so I doubt that is the only problem, mixed thoughts on here as regards wonder egr cleaners.
Pulling well and good fuel economy tends to say your injectors are in decent shape but I'd try a good shot of fuel cleaner and an italian tune up and see if it makes a difference, maybe a new set of filters while you're at it.
Make sure everything is nicely up to temperature when he does the test.

Yeah im thinking the same regarding the injectors.
The filters have all been changed less than 1000miles ago along with oil. The egr was fitted six months ago along with a good old manifold clean out while i was at it. however the egr was never allowed to work because the solenoid was broken. Thats been fixed today ....I managed to get a hold of a free 407 solenoid and all connections and mounting bracket fit my 406 perfectly .
I'm planning on running some dipetane through it before the next test so hopefully that combined with the functioning egr and an Italian tune up will sort her out.

[dummysock]

Try some Forte Diesel additive
My MOT tester swears by it. He has failed cars on emissions and then added this and they then pass

[madmadmax]

an Italian tune up will bring the emissions down a long way

[keppler]

Did a leak back test on friday and the injectors got a clean bill of health. Ive been told by others that reconnecting the egr valve is going to slightly increase the smoke readings, so im completely confused now

[madmadmax]

when did it last have a service?
what type of driving do you do in it?
what mods have you done to it?

it could just need a service and a good thrashing down the motorway at 5,000rpm but staying within the speed limit

i have a 90hp 306 that got a 0.5ppm with the egr valve unplugged and it's driven hard

[keppler]

It was serviced about 1000 miles ago.
Most driving is done on the motorway and national primary roads but normally i just stick to 70mph for economy. For the past month I've just been doing a lot of short runs around town but I did take her for a quick 10 or 15 mile spin up the motorway at 3000rpm right before the test.
No mods that I know of mate.

I replaced the maf sensor about six months ago with a non original one from ebay so I'm a bit worried about that.

[madmadmax]

the cat can get clogged up and give hi smoke readings, you have got me grasping at straws for what to go for next

best thing to do is to knock the cat out and see if the mot place will put it on the tester just to see if it would pass

[keppler]

Yeah I'm just gona top it up with dipetane and run the hell out of it for the next few weeks. Tbh I think its more than likely I've been driving it like a granny for the past 20k miles and as you say the cat is just a bit blocked up.
Just out of a matter of interest, are you saying that if i take the cat out, it would have the effect of reducing the smoke reading? I was always under the impression that the cat reduced emissions. Im asking this because I have a good mate who's a dab hand at welding and Im fairly sure I could get him to remove my cat, hollow it out and weld it back in.

[jasper5]

Drain the fuel filter housing, pour in some Forte (as dummysock suggested) then run the engine at high revs for a few minutes and problem solved.

My Expert 2.0 HDi only just passed the emission test recently, a tin of good quality injection cleaner soon sorted it out.

[madmadmax]

diesel cats don't affect the smoke much thay are for nox and other gasses, thay do clog up over time with larger partials of soot which pushes the smoke reading up