MOT FAILURE 03 plate

[beezasport]

Hello! My car failed the MOT today with:

001 Exhaust emissions hydrocarbon content after 2nd fast idle excessive [7.3.2b]

The reading was 1.058....the readings you are allowed is 1.030 MAX and 0.970 Min

does anyone know what this could be?

MOT tester said maybe there is a hole in the exhaust and it's pulling O2 in there.

Please help!!

Thanks

 

[beezasport]

the car has standard exhaust and no map either...

 

[Tom B]

Find the hole, fix the leak and run it again. A tenporary repair might get it through the MOT (certainly worked on my old MK2!) but you'll probably need a need a new exhaust in the near future.

 

[beezasport]

I'm not sure if it is that though. the tester said he couldn't remember if the numbers meant it was running rich or lean.

 

[DodgyDave]

book it in again, but for one hour beforehand drive the car ... and on the way to the MOT place drive it hard......

That'll get the exchaust & CAT temps up fully and it'll be fine - just get 'em to test that as soon as you arrive.


Dave

 

[ibizacupra]

reading >1.000 are leaner (so air leak is plausable) and can be very small and still account for this. If you have vagcom, you can look at what the car thinks its lambda is in block 30/31/32

 

[beezasport]

cheers bill ill check that tonight and repost

 

[beezasport]

Is hydrocarbons not unburnt fuel?

 

[ibizacupra]

Is hydrocarbons not unburnt fuel?

you have quoted the lambda max/min values not the HC one.
Do you have the print out of them?

HC is unburnt fuel you are correct.

HC, CO, Lambda all emissions readings

 

[beezasport]

no i've not got the printout the guy told me the values (1.058 these are the lambda values)but on the failure report it said:
001 Exhaust emissions hydrocarbon content after 2nd fast idle excessive [7.3.2b]

i'll go log 30 31 and 32 and post the reults.

 

[m0rk]

you only need to log it at idle, with no load

and about 2500rpm, with no load

ie - do it on your driveway

 

[beezasport]

Ok took the car out got it nice and warm and did these logs
i'mnot sure how to insert exel onto here...sorry
IDLE:
Group A: '030 Group B: '031 Group C: '032
Pre-Cat O2 Post-Cat O2 Lambda Factor Lambda Factor Bin. Bits Bin. Bits Idle O2 Adapt Run O2 Adapt
TIME 111 110 TIME TIME -10.1 -10.1
MARKER STAMP STAMP STAMP % %
0.95 111 110 0.02 1 1 0.46 0.6 -7.8
2.46 111 110 1.45 1.008 1 1.96 0.4 -7.8
3.98 111 110 2.97 1 1 3.47 0.4 -7.8
5.37 111 110 4.38 1.008 1 4.87 0.6 -7.8
6.68 11 110 5.79 0.992 1 6.19 0.6 -7.8
8.09 111 10 7.19 1.008 1 7.69 0.6 -7.8
9.59 111 110 8.6 0.984 1 9.1 0.6 -7.8
11.11 111 10 10.1 0.984 1 10.62 0.6 -7.8
12.62 111 110 11.61 1 1 12.12 0.6 -7.8
14.14 111 10 13.13 0.984 1 13.63 0.6 -7.8
15.62 111 110 14.64 1.008 1 15.13 0.6 -7.8
17.14 11 10 16.14 1 1 16.65 0.6 -7.8




2500RPM

Group A: '030 Group B: '031 Group C: '032
Pre-Cat O2 Post-Cat O2 Lambda Factor Lambda Factor Bin. Bits Bin. Bits Idle O2 Adapt Run O2 Adapt
TIME 111 110 TIME TIME -10.1 -10.1
MARKER STAMP STAMP STAMP % %
0.78 111 110 0.01 1 1 0.37 0.6 -7.8
2.08 11 10 1.18 0.992 1 1.58 0.6 -7.8
3.39 111 110 2.48 0.992 1 2.9 0.6 -7.8
4.59 11 110 3.79 1.008 1 4.19 0.6 -7.8
5.81 111 110 5.01 0.984 1 5.41 0.6 -7.8
7.01 111 110 6.21 1 1 6.61 0.6 -7.8
8.32 11 110 7.42 0.977 1 7.82 0.6 -7.8
9.63 111 110 8.72 1.008 1 9.23 0.6 -7.8
10.94 111 110 10.13 0.992 1 10.53 0.6 -7.8
12.14 111 110 11.34 0.992 1 11.74 0.6 -7.8


MORK i feel just like your avitar at the moment!

 

[beezasport]

Looks like a leak in the exhaust as them readings are ok (as far as i can see) im no expert though..can anyone confirm?

 

[bcstudent]

The log looks fine to me. A lambda reading of 1.058 is about 15.55:1 AFR...pretty damn lean. I guess it's down to an exhaust leak or a dodgy emissions test probe.

 

[kez]

james> good excuse for a piper

 

[RikH]

spoke to james last night and we compared his logs' to my emissions readings from last year (with standard exhuast) so we're thinking that seen as MOT readings are taken from back of the exhuast with the probe there must be a hole between lamda 2 and the back of the system..........

im going to book mine in early, run it on tesco 99 and RAGGGGGG it before it goes in

 

[beezasport]

Got the car up in the air today... there was a sleve on the exhaust and it was pulling air there!
Thans for all the help Guys!!!!!

KEZ i needmoney for that wanna buy some stuff off me!

Rik got the reading down to 0.010 today the same as your standard exhaust. Can we use VAG-COM on yours to check the CO readings before and after the cat blocks 30 31 32, one of them is Lambda probe (not sure though)

 

[RikH]

yeah can do, ill head over early tomorrow so have the laptop charged up as the cat should be hot enough after the drive over there

 

[beezasport]

Gotta be there at 10am so you wanna be here about 9