MOT - emissions test

Legacy_user

My car failed its MOT on emissions - the CO level was high, and the lambda value 1.04.

The garage know me as an old customer. When I asked what I should do, the tester gave me half a wink and said he would get it through. At the retest the CO value was nil and lambda 1.00. He said all he did was add half a bottle of Wynns petrol additive No. 3 and run the engine for a few minutes.

Obviously I am pleased at the result, but just a bit suspicious that there is some trick which testers can use for favoured customers. I had previously serviced the car, added injector cleaner, and taken it in straight after a vigorous Italian tune-up, but it still failed. Yet the tester could miraculously achieve zero emisions with just a bit of additive.

UsernameAlreadyExists

Who cares about emmissions? It's not like it affects the "safety" or "road-worthiness" of a car.

Horizon81

UsernameAlreadyExists wrote: »

Who cares about emmissions?

What about the rainforests? Global warming? Yes I'm being sarcastic. It's all part of the nanny state and more reasons to extort money out of people.

As for the OP, you did everything right - took it for an italian tune up before you took it in. I assume it was done while you wait, engine still up to temp, rather than sitting round a few hours? I also find it strange that you added some fuel injector cleaner, but it failed, then they added the Wynns and it passed. If it's true then it's a good endorsement for Wynns No. 3.

forgotmyname

What about the children? Your killing the planet etc etc etc...

He probably retested it at different revs Or maybe even a different car..oops shhh dont tell anyone that..
Its amazing how many times a car passing the machine suddenly gets a pipe shoved up its exhaust. And the car outside gains a pass.

My MOT guy hates diesels with cambelts. He had one that failed during the emissions test. Although it states this is the customers problem it gave him aggro for some time.

Now he revs them as little as he can get away with. Result is usually a lower reading on the smoke test also.

[Deleted User]

Faked it like what Kwik Fit did with me after getting £20 out of me for BG44K fuel additive which did nothing. I later got the £20 refunded by cheque from Kwik Fit HO.

benjus

When I picked up my car after its last MOT the guy told me it initially failed on emissions but not to worry, they'd sorted it. When I asked what they did, he just got a bit vague and said something about just putting it through again. Didn't charge me anything extra, so I don't care how they did it...

skivenov

Sounds like they might have "accidently" put the probe in the wrong car when they retestted the emissions.

Naughty, but gets the result

red_eye

benjus wrote: »

When I picked up my car after its last MOT the guy told me it initially failed on emissions but not to worry, they'd sorted it. When I asked what they did, he just got a bit vague and said something about just putting it through again. Didn't charge me anything extra, so I don't care how they did it...

cold cat. some times the warm up the gas analyser allows is not enough. having the emissions test right after a good run will pass unless there is something else wrong

red_eye

skivenov wrote: »

Sounds like they might have "accidently" put the probe in the wrong car when they retestted the emissions.

Naughty, but gets the result

leads are not long enough. you have a probe in the tail pipe, another on one of the HT lead and one in the dip stick

mcjordi

red_eye wrote: »

leads are not long enough. you have a probe in the tail pipe, another on one of the HT lead and one in the dip stick

not on any MOT ive had mind...

red_eye

mcjordi wrote: »

not on any MOT ive had mind...

with out the HT probe how would the analyser know what rpm the engine is doing? the tester could be idling the engine when the analyser is measuring fast idle emission.