Emmisions MOT failure, advice please.

[Leeland]

Took my 54 plate vrs for an mot today, failed on emmisions, took it out and drove it 'enthusiasticly' on a30 for about 20mins, the mot people put in an

additive first. Went back to re-do test but it still failed :S

Have got it booked in for next weekend to re-do emmisions test, intend to drive it with intent for the week, have filled up with 'Total Excelium' diesel

and intend to go out a good hour before the retest to get the engine hot and will leave it running when I get there, any other advice would be most

appreciated.

A question for the experts also, had an engine re-map to 180bhp in October, would that effect emmisions??

Even though I'm on 'Excellium' and the additives the test center put in, can I add anything else to help??

Thanks

[richwarwicker]

what exhaust system are you running? a fault with the exhaust will ruin your emissions test.

[sharkrider]

have you tried checking the MAF sensor, and making sure the air filter isn't clogged up? remap shouldn't affect MOT emissions pass...

[Decron]

It didn't fail the emissions test because it didn't have one. It failed the smoke test and that is hard work but remaps can do this as they is an element of fueling changes made. Also the smoke test should be done at a consistant engine temp which they should test so "warming it up" is a waste of time and fuel. The majority of "black smoke" issues are caused by over fuelling so it is likely that the remap could have done this if there is no other fault.

Change the air filter and run some Forte through it (Neat from the fuel filter), see how it does then.

Edited 16 January, 2010 by Decron

[Leeland]

what exhaust system are you running? a fault with the exhaust will ruin your emissions test.

The exhaust system is standard.

have you tried checking the MAF sensor, and making sure the air filter isn't clogged up? remap shouldn't affect MOT emissions pass...

Thanks, I'll check the air filter in the morning, can that be a significant factor, if dirty?

[ric04vrs]

remap shouldn't affect MOT emissions pass...

it depends how much extra fuel is being thrown in, too much, and it will fail the smoke test, and whatever you do with regards to additives or fuels, it probably wont pass

[MoggyTech]

It will be the remap. 180BHP is an aggressive map. The smoke density test is done at 2,000 RPM then full throttle. The test looks at the sustained density and not any acceleration fueling smoke. So basically the car is over fueling all the time.

[cheezemonkhai]

Absolubtly put a new air filter in.

If you have not had one in the last 10k miles, it will be dirty and causing problems and byu 40k it will be like a block of soot.

If you are willing, give the car a double dose of millers power sport 4 (or whatever they have called it now) or dieselclean if it's suitable for your car.

Then drive it like you stole it for a while (once warmed up) and fill up again with a single dose of the millers.

Should hopefully see you through the MOT.

[Leeland]

It will be the remap. 180BHP is an aggressive map. The smoke density test is done at 2,000 RPM then full throttle. The test looks at the sustained density and not any acceleration fueling smoke. So basically the car is over fueling all the time.

How do some of the members on here pass when running 250bhp or more, excuse my lack of knowledge, I'm seriously considering

getting mine put back to standard, which they'll do for 50 quid.

I was only going to get it mapped to 160bhp, but when tested as standard it was 142.6bhp, which apparently is typical for that engine,

so instead of going for 160 it ended up at 178.9bhp, they assured me there would be no issue with the clutch but I never thought about

emmisions

Absolubtly put a new air filter in.

If you have not had one in the last 10k miles, it will be dirty and causing problems and byu 40k it will be like a block of soot.

If you are willing, give the car a double dose of millers power sport 4 (or whatever they have called it now) or dieselclean if it's suitable for your car.

Then drive it like you stole it for a while (once warmed up) and fill up again with a single dose of the millers.

Should hopefully see you through the MOT.

I will try this, thanks, but as above I'm having worries about the re-map, my MOT expires on the 21st , my emmisions retest is on the 24th,

I have paid for the MOT and have the paperwork, what 'grace' do I have?? If any :think: :think:

[ric04vrs]

the 250bhp cars might have better mapping and hence less smoke at the required emission test rpm

[Confused_Cheese]

Not sure what you mean by grace but...

Legally you get 10 days for an MOT retest, but when your current MOT expires you can only drive to either a garage to get it fixed, or to an MOT test centre for a retest.

Oh and you only get one retest without needing to repay... sounds like you already had one retest so technically you need to pay again unless they were being nice

See posts below!

Edited 16 January, 2010 by Confused_Cheese

[MEDIX999]

A remap should definately not in theory cause this, as stated many have remapped cars and they pass mot's, a remap should infact lower your CO2 emmisions as its burning more efficiently.

[richwarwicker]

Oh and you only get one retest without needing to repay...

no you dont, if the car leaves the MOT test centre premises, the tester can then charge you a partial retest fee if you dont return before end of the next working day, which is half price, some do and some dont, if you dont retest within 14days they can charge you a full MOT test fee again

quote below from http://www.dft.gov.uk/vosa/repository/MOT%20test%20fees%20and%20appeals.pdf which is a PDF of full mot test fee rules

Retests (Re-Examinations)

Providing the testing station has not changed ownership:

If the vehicle is brought back to the same test station and retested before the end of

the next working day on one or more of the following items only:

No Additional Fee (Partial Re-Examination)

Bonnet

Lamps (excluding head-

Seats

VIN

Bootlid

lamp aim)

Sharp Edges or

Windscreen and Glass

Brake Pedal Antislip

Loading Door

Projections

Windscreen Wipers

Direction Indicators

Mirrors

Steering Wheel

Windscreen Washers

Doors

Rear Reflectors

Tailboard

Wheels and Tyres*

Dropsides

Registration Plates

Tailgate

* not classes 1 and 2

Fuel Filler Cap

Seatbelts (excluding

Towbars (excluding

Hazard Warning

body around anchorage

body around anchorage

Horn

points)

points)

If the vehicle is left at the testing station for repair and is retested before the end of 10 working days following the day of the initial failure, then only a partial retest is needed for which no fee may be charged. If the vehicle is removed from the testing station for repair and returned for retest within

10 working days following the day of the initial failure, then only a partial retest is needed and a partial retest fee may be charged.

Only one Partial Re-Examination is permissible per full examination

Edited 16 January, 2010 by richwarwicker

[Confused_Cheese]

no you dont, if the car leaves the MOT test centre premises, the tester can then charge you a partial retest fee, which is half price, some do and some dont, if you dont retest within 14days they can charge you a full MOT test fee again

Sorry, i actually googled to make sure but the site I got it from must be wrong! I should of got off my fat ass and checked my last failure certificate lol :( will edit my post

Hmm the first part of your post is wrong mate, your quote says 10 days not 14! So at least I got something almost right lol

Edited 16 January, 2010 by Confused_Cheese

[richwarwicker]

Sorry, i actually googled to make sure but the site I got it from must be wrong! I should of got off my fat ass and checked my last failure certificate lol :( will edit my post

Hmm the first part of your post is wrong mate, your quote says 10 days not 14! So at least I got something almost right lol

please see my edited post, i've changed what i put and included a PDF link to the government recommended charges, we were both a bit right and a bit wrong

[richwarwicker]

10 working days is 14 real days so i wasnt far wrong,

[richwarwicker]

i also found this while i was looking for the test fees and is vehicles exempt from MOT at any age

Types of vehicle that do not have

to take an MoT test.

a Motor tractors

b Track-laying vehicles

c Articulated vehicles that are not

buses (Bendi buses) or lorries

d Works trucks

e Invalid carriages weighing no

more than 306kg when unloaded

f Vehicles used only to pass from

land occupied by the person

keeping the vehicle to other

land occupied by them, and not

travelling on the road for more

than a total of six miles a week

g Hackney carriages or

private-hire vehicles licensed

by local authorities authorised

to check the roadworthiness

of these vehicles

h Hackney carriages (vehicles

licensed to carry passengers)

getting tax discs from Transport

for London

i Vehicles provided for police

purposes and maintained

in an approved workshop

j Goods vehicles powered

by electricity

k Trams

l Trolley vehicles that are not

auxiliary trolley vehicles (auxiliary

trolley vehicles are vehicles

that are adapted to run from

power provided from a source

on board when it is not running

from power from some outside

source)

m Vehicles authorised to be used

on the road by a Special Types

General Order made under

Section 44(3) of the Road

Traffic Act 1988

n Vehicles used only on certain

islands that do not have a

bridge, tunnel, ford or other

suitable way for motor vehicles

to be conveniently driven to a

road in any part of Great Britain

[mannyo]

Once you have changed the filter, then get a friend to look at the exhaust smoke before going back for the retest.

As posted earlier, the smoke during the rpm increase does not matter, its what happens at the sustained rpm that counts. So increase revs to 2000 rpm and hold it there, there should be little if any noticable smoke. Now dont be scared about the next bit as the testers do it, foot on the floor and hold the car on full throttle, once max rpm is reached there should be little or no smoke. Again any excess smoke as the car reaches max rpm does not count.

If its still smoking, it could be the maf or just a poor quality map.

[ric04vrs]

A remap should definately not in theory cause this, as stated many have remapped cars and they pass mot's, a remap should infact lower your CO2 emmisions as its burning more efficiently.

its a diesel smoke test, nothing more, no CO2 checking is involved

it is CO ( and other nasty chemicals) that are checked on a petrol engined vehicle during an MOT test