Help! mot fail

[pap29]

ok so i took my car in for an mot on friday and wasn't really worried, i normally run around with a free flow exhuast system but mot time so put the cat in which from what i can remember is alll i did to pass last year, this mean i have 1 cat in which is known as the 2nd cat, anyway so with that in it failed and im really stumped, the results were
fast idle test
co 0.51
hc 136
lamba 1.02

2nd fast idle test
co 0.46
hc 142
lamba 1.02

these co readings should be below 0.3

natural idle is 0.48 which is below the 0.5 so its fine btw.

my engine is standard apart from janspeed cat back, janspeed downpipe and frankspeed manifold, and k&N panel filter.
really need help guys!? please :down:

 

[Retepetsir]

Leak in the exhaust somewhere? What were the other readings, i.e. lamdba, etc?

It's running pretty rich by the looks of things. Did you make sure the cat was nice and hot before the test?

If you've got 2 cats in you should pass it easily. I can get my K11 to pass with just 1!

 

[frank]

i think a high co means its running too rich lambda problem maybe ?
if you,re running the 2 cats, i doubt it would be a cat problem personally, you could check the lambda voltage (middle wire) to see if its going into closed loop eh

 

[pap29]

i have added the rest of the details and no it only has 1 cat in it for mot time and no cats normally

 

[frank]

i have added the rest of the details and no it only has 1 cat in it for mot time and no cats normally

ahh, i think you,re gonna need that 1st cat personally
mine got a very low 0.003% with the 1st cat only, opened manifold and 1.6 t/b and injectors
(printout in my blog)

 

[pap29]

well i got a 0.01 last year without the 1st cat just the second since my cars only a 1 litre.
so whats my next cause of action do i buy a new cat? lamba? ill go now and check my timing to see if its running rich

 

[frank]

if your lambda is reading between .3v and .6v at cruise (once hot) then i doubt it would be the lambda (has your 2nd cat got damp/corroded while removed ?)

 

[pap29]

my cat was stored up on the timber inside my garage in bubble wrap but i might have knocked it off once if my memory serves me well, would dropping it like that caused a problem?

 

[pap29]

just for reference when it failed last year when i tried me luck with no cats in it was alot higher co then this years details as above.

 

[pap29]

o and does anyone know if cats can be put in the wrong way?

 

[Alienfish360]

MOST CG10's won't pass without the first cat, which is why most CG10 owners with janspeeds swap them over for MOT.

 

[pap29]

dont have first cat anymore as it passed with just 2nd last year.
so would have droppping it caused problems?
could it be in the wrong way round?

 

[ollyc98]

I don't think they work backwards, but I don't think they fit on backwards either, flip it around and replace your lambda sensor as they're cheap enough.
Also check the system for leaks

 

[pap29]

good news i put my car back in for a retest this morning and it past with flying colours!
all i changed was took out the panel k&n and put back in the standard paper filter and the emmisions dropped from 0.46 (k&n) to 0.01(standard filter), couldn't beleive the effect
so for people worrying about emmisions they should only need paper filter and seconary cat