MOT Fail

RedRocket1

Club Member (Trial)
So i failed my MOT, on a pretty good list for the cars age. But one of the failures was on emissions. I have the 4-2-1 janspeed with full system but with the 2nd cat on. I was under the impression it would pass with the cat still on.

"Exhaust emissions carbon monoxide content after 2nd fast idle excessive"

Anybody shed some light so i can get it fixed ASAP.

Cheers(Y)
 
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RedRocket1

RedRocket1

Club Member (Trial)
I'm not sure mate. When i went and picked the car up, the guy said that it was running a little rich.
 

frank

Club Member
i think you will really struggle with the 2nd cat only, you could try heatwrapping it maybe ?
 
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RedRocket1

RedRocket1

Club Member (Trial)
Well i might as well just put on the standard exhaust back on. Gives me a chance to hack the janspeed up to get it to the right length anyway. I just thought it would be ok with the 2nd one on but obviously not, ######in global warming!!
 
Well i might as well just put on the standard exhaust back on. Gives me a chance to hack the janspeed up to get it to the right length anyway. I just thought it would be ok with the 2nd one on but obviously not, ######in global warming!!
My old micra passed emissions with only 1st cat! I spliced in a straight piece when the 2nd cat broke at the weld.
But then our MOT is done in a government test centre (Things are either right or wrong, and they aren't making work for themselves), not the local garage down the road
PS. Have you checked your air filter isnt blocked?
 

pollyp

Club Member
the janspeed manifold with stock ecu mapping wouldn't barely pass emissions. the 2nd cat is just so far away its barely hot enough even with a new cat. the primary cat was right up there really hot working efficiently. i just put my stock back on for mot, bit of a hassle but tis only once a year
 

mikey

Ex. Club Member
Mate, did you swing by today? Sory if ya did, I got roped into something eh! I'm gonna put a standard system on just to be sure, other than that it's the demonic rust we gotta worry bout :p
 
Mate, did you swing by today? Sory if ya did, I got roped into something eh! I'm gonna put a standard system on just to be sure, other than that it's the demonic rust we gotta worry bout :p
The dreaded rust mites strike again!
sills and lower cross member?
 
The wording 'Failed after 2nd cat test' is only to do with the manner the emissions are tested.
When the tester checks the emissions the emission tester will instruct the tester to hold the revs at a fast idle (between 2500 and 3000 revs)
The machine will measure the CO, HC and Lambda. If the measurements do not fall below the legal limits the tester will prompt the tester to carry out a 2nd, longer test. That longer test is the 2nd emissions test.

If your car has no cat it won't pass the cat test. No matter who mapped it and no matter if you heatwrap the exhaust or not. The emissions test is to check the function of the cat. If the cat doesn't work or if they have been cut out it won't pass.

The only way round it is to fit the original manifold/cat, then refit your go faster one after. On most cars, providing the first cat is working ok you will be able to pass the test with the secondary cat removed. I've tested quite a few cars with that set up without problem.

You used to get away with claiming the engine had been replaced with an engine from before 1992 but nowadays most MOT stations will tell you to take a run and jump if you tell them that! LOL!
 
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RedRocket1

RedRocket1

Club Member (Trial)
Mate, did you swing by today? Sory if ya did, I got roped into something eh! I'm gonna put a standard system on just to be sure, other than that it's the demonic rust we gotta worry bout :p
Nah i couldnt get out of work mate, im gonna take tomorrow off if you wanta get these beasts legal haha.

My rust spots are on rear sills and rear arches but hardly any....just enough for the guy to point it out.

Well im thinking im gonna put on the 1st cat (with the help of Magic Mikey) and see where we go from there. The other stuff he failed me on is just stupid, apart from brakes....not so stupid :D
 

mikey

Ex. Club Member
Good plan man...my sills are kinda covered by the skirts anyhoo...doubt that'll stop a pokey thing examination :glare: well the first port of call is the scrappy for a downpipe, have you got yours from Stani's place? I was gonna use the SR's but it's been monstered by rust beasties lol and we should, as recommended, just get standardised for the farty-emissions test eh, so speedy jans off, regulars on!


Nah i couldnt get out of work mate, im gonna take tomorrow off if you wanta get these beasts legal haha.

My rust spots are on rear sills and rear arches but hardly any....just enough for the guy to point it out.

Well im thinking im gonna put on the 1st cat (with the help of Magic Mikey) and see where we go from there. The other stuff he failed me on is just stupid, apart from brakes....not so stupid :D
 
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