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[Fran]

My car has failed on emissions, I've been told by different people exhaust (had that checked - ok), the censor (one said he had looked at that) and if not I'm now advised to get the electrics looked at - engine management, if not could be the cat.

When it failed the reading was quite high, I had an oil and air filter change (haven't done anything else) and (but according to a different garage) the level has only just failed.

Is there anything I can do to get the levels down? Would giving everything a clean under the bonnet help?

I was also told that I should run it before taking the test again - would a trip up the motorway or dual carriageway be enough to bring it up to a pass if I did that just before taking it for the re-test (if it really is that marginal).

[MarkyMarkD]

Giving it a good hard run may well help. Even better you can get additives which you put in the petrol which will clean things up - add them before you go for the blast up the m/way or dual carriageway.

And watch out for speed limit compliance

Can't remember the name of the additives but somewhere like a motoring accessory shop/garage/Halfords would have it.

[Fran]

Thanks I'll try that. Hope it passes though. :

[jack_pott]

My insurance man's car failed on emissions. The Rover dealer said £500 for a new engine, a local mobile engine tuner fixed it for £50!

[zain]

How old is your car? & model?
Mine failed last month and is only 3 years old. I payed £40 to get the sensors cleaned and used some cataclean ( i think it was called that) and took it for a good run on the nearest motorway. This solved it.

[skiddy2k]

do you have a bluish or black coloured exhaust fumes? when you accelerate?

try looking when your car is stationary, stand outside car, put foot on pedal.

[scamreporter100]

Originally Posted by zain

How old is your car? & model?
Mine failed last month and is only 3 years old. I payed £40 to get the sensors cleaned and used some cataclean ( i think it was called that) and took it for a good run on the nearest motorway. This solved it.

CATACLEAN ANOTHER FUEL ADDITIVE SCAM

CataClean

The fuel additive company CataClean makes remarkable claims; they are now trying to break into the American market after ripping of many people in the UK. Investigations by the ASA into Cataclean found the company's (CataClean Global Ltd & System Products (UK) Ltd which is run from a small porter cabin in Liverpool United Kingdom) marketing plan is fraught with false and misleading statements, which the ASA started to investigate after receiving many complaints," read the full report at http://www.asa.org.uk/asa/adjudicati...c/TF_ADJ_41571 The Director Ross Baigent has a history of fuel additive company scams and is linked to a major fuel additive fraud in Australia, Firepower run by his business partner Tim Johnston.

[Paparika]

Mine failed the emissions too, then again they broke my handbrake and denied it on Thursday... so i don't know if i believe them.

I paid another £50 odd pounds to have the something done that probably would of cost me a £5 to do my self but it passed 2nd time

[taxi97w]

After the 3 years warranty ran out on my car, I took it to the main dealer for it's MOT. Dealer said it had failed and said it would cost over 200 for a new cat. I was livid and said give me the keys, I'm otta here. After trying to get me to see sense, which I wouldn't, they said they would hook up another car (same model as mine) to the testing apparatus and get it passed, which they did! Didn't cost me owt.
The next year took it to the council testing centre cause I thought the main dealer from last year was trying it on. Council said it had failed, so asked me to take it for a long run and bring it back where they would test it again. Brought it back, it failed, I went all "Oh, no really, it's such a young car, this can't be happening". They also rigged up the apparatus in the end, and passed me.
The year after that, took it in for a small service first and it passed OK. So much for the new cat!!
Didn't do anything to it this year, just to see what would happen this time, it passed completely.
What do I think of all this? Some'll try to scam you, others will try to scam the system to help you.

[kaisersoze]

Mine failed, so the garage gave me some cleaner to put through the enginge (free of charge) and told me to give it a good run. Took it back an hour later, passed first time and didnt charge me anything extra. Not bad on a 10 year old car.

[The Pedant]

A new cat does seem somewhat extreme. Last time my car failed on emissions, the garage themselves drove it around the block to pass it. It just needed a little warming up properly (I'm only a mile from the garage). Thankfully they did all this without even bothering me.

Everyone I have known who's failed emissions, has subsequently passed when driven round the block or retested (on the same or sometimes another test rig).

You might want to have a word with friends/colleagues in the area, to see if they have anyone they can recommend for next time.

[Paparika]

Originally Posted by The Pedant

A new cat does seem somewhat extreme. Last time my car failed on emissions, the garage themselves drove it around the block to pass it. It just needed a little warming up properly (I'm only a mile from the garage). Thankfully they did all this without even bothering me.

Everyone I have known who's failed emissions, has subsequently passed when driven round the block or retested (on the same or sometimes another test rig).

You might want to have a word with friends/colleagues in the area, to see if they have anyone they can recommend for next time.

Wish mine had done that for me, although now i know never to take the car to the garage first thing in the morning now, i live right by a motorway so will run it on that first, oh and not to go back the the same garage who did it last week

[Pssst]

The emissions check should be done when the oil temperature has reached a minimum temperature. MoT testers should insert an oil temp probe into the engine usually via the dipstick hole. Only then should the test be completed. It is unusual for a modern car with an ECU/fuel injection system to fail on emissions. My near 17 year old Golf has never failed on emissions.

[Nile]

I'll move this thread to the 'Motoring & Public Transport' board.

Hi, Martin’s asked me to post this in these circumstances: I’ve asked Board Guides to move threads if they’ll receive a better response elsewhere(please see this rule) so this post/thread has been moved to another board, where it should get more replies. If you have any questions about this policy please email abuse@moneysavingexpert.com.

Nile

[anewman]

Originally Posted by Pssst

The emissions check should be done when the oil temperature has reached a minimum temperature.

I believe they check the coolant hoses are hot and if it passes then it's passed. If it fails then I believe they check the oil temp and perform a slightly different emissions test.

When thrashing a car you don't need to go fast, just use lower gears and rev the engine a bit harder - best to wait till the engines warmed up a bit first before thrashing it though. I would put a double dose of redex in the petrol tank (petrol injection variety if for a petrol injected model). If this doesn't work then you'd be starting to look at the temperature sender (though if this failed there'd usually be noticeable running problems), then the more expensive Lambda sensor, or even the more expensive still catalytic converter.

Cleaning things under the bonnet may well make things look nicer, and stop the car from starting and damage expensive electrical components if done incorrectly, but won't reduce emissions

[asbokid]

things to do if your car fails the emissions part of the MOT test..


new sparkplugs - about £8 for a set of standard quality

new HT leads - about £25

new air filter - about £6

check the ignition timing - a cheap strobe gun costs about £10 to DIY.

new lambda (O2) sensors - these sensors can be bought for £10 in a universal form and then spliced onto the proprietary connectors used in the car

new catalytic converter - around £30 - £50 for most popular cars

reset the car's ECU to clear any memorised engine faults. Typically, when an engine fault occurs, the engine's computer (the ECU) runs the engine in 'limp mode'.

When the engine is running correctly, the ECU normally adjusts the fuel-air mix on a dynamic basis, according to data received in real-time from the engine sensors.

However, when the engine is crippled and running in limp mode, the ECU uses a static table of data for fuel-air mapping. This is inefficient and can cause excessive exhaust emissions.

Obviously it is sensible to remedy any engine fault, but some faults can be transient, or one-offs (e.g. a temporary electrical sensor fault is often triggered by driving through a flood).. However, these faults may still be memorised by the ECU, affecting the overall efficiency and performance of an otherwise healthy engine.

Resetting the ECU could clear these faults, and help your car to pass the MOT emissions test.

[vaio]

Originally Posted by asbokid

things to do if your car fails the emissions part of the MOT test……….
………new catalytic converter - around £30 - £50 for most popular cars

I think you are missing a zero here

[asbokid]

Originally Posted by vaio

I think you are missing a zero here

cats for many popular cars are available for under 50 quid..

http://www.cats-direct-shop.co.uk/

i would expect the fitting cost to be under £20 including any new gaskets needed.

[vaio]

thanks for the link, way cheaper than I thought

[anewman]

Problem is the cheapie cats will have failed come next MOT. Better to buy the OE one if you want it to last. Often similar for the Lambda sensors, but if you look on Ebay Bosch ones can be gotten hold of relatively cheap (compared to Mfr's prices).

Bad HT leads would usually reveal themselves in running problems or obvious sparks when the running engine is viewed in the dark.

Timing is usually handled by the ECU now so a strobe gun is useless. There are usually just marks to line up, and these would only be incorrect if a timing chain had stretched for example.