Cerbera MoT emission levels?
Cerbera MoT emission levels?
Author
Discussion

ridds

Original Poster:

8,372 posts

274 months

Thursday 30th April 2009
quotequote all
What are our cars supposed to be tested against?

I thought our limits were slightly different to cars of comparable age.

Can anyone remember what they are?

ridds

Original Poster:

8,372 posts

274 months

Thursday 30th April 2009
quotequote all
Need the info for my MoT tomorrow...... winkhehe

diycerb

556 posts

261 months

Thursday 30th April 2009
quotequote all
From my VOSA book, every MOT station should have one.

Max CO limit (% vol) 0.5 @ idle
Max CO limit (% vol) 0.3 @ fast idle
Max HC limit (ppm) 200
Min Lambda 0.9
Max Lambda 1.2
Min RPM 2500
Max RPM 3000

The only difference to a normal car is we get a much wider tolerance on the Lambda reading usaully its 0.97 - 1.03.

Good Luck.

Rich.

ridds

Original Poster:

8,372 posts

274 months

Thursday 30th April 2009
quotequote all
hahaha Lambda limit 0.9-1.2. Excellent.

Cheers Rich.

fatjon

2,299 posts

243 months

Friday 1st May 2009
quotequote all
A useful tip. Before doing the test hold it at 3500 rpm for a couple of minutes to get the cats good and hot then test it quickly! Mine failed miserably until we did this then it passed, though only just.

tur8o

176 posts

229 months

Friday 1st May 2009
quotequote all
hi, mine has just failed the mot on emissions (too high). tried getting it really hot before taking it and although it made a difference it still failed. does this definately mean its the cats or could it just need the ecu and lambda sensors checking/adjusting?

ridds

Original Poster:

8,372 posts

274 months

Friday 1st May 2009
quotequote all
Can you tell us results you got.

Also did you try the other bank? wink

Storer

5,024 posts

245 months

Saturday 2nd May 2009
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Got my local MOT chap to test mine without Cats just to see what it was.

HC was 1100 ppm
CO was 1.2%

He said Cats would bring those down but I suspect they will still be borderline.

The backfire and flames we get kill a catalytic converter very quickly. Apparently there is little point in paying £500 per cat as they will only last marginally longer than a £250 one.

After the trip up to Chatsworth I have decided the car needs to be quieter so I am going to fit them and leave them on.

jammy_basturd

29,778 posts

242 months

Saturday 2nd May 2009
quotequote all
Another nudge towards having both CATs and de-cat pipes. Just fit the CATs for MOT, will save them then and make them last much longer.

In fact I thought someone had a pair that PH members could borrow just for this reason?

tur8o

176 posts

229 months

Sunday 3rd May 2009
quotequote all
hi, ive only briefly spoke to the guy in the office at the garage not the mechanic. but i think he said the 1st test it was at 9 the car has been left standing in the garage for about 8 though having a new clutch and service done. after they ran it on the rollers for a while and took it back to mot station it had come doen but only to about 4. not sure if they checked both banks. will find out more on tuesday. just dont want to buy two new cats to find out just needed setting up or a new sensor.

Allandwf

1,773 posts

225 months

Sunday 3rd May 2009
quotequote all
They are very marginal. I had three people on mine and it took three attempts to get everything to stay green for the required amount of time.
one guy on the throttle, one moving the probe about to get the best reading, and a third blowing an airline through the radiator !! Took a 45mins just for the emmissions.

itiejim

1,822 posts

235 months

Sunday 3rd May 2009
quotequote all
Why are they so marginal?

Is it due to fueling - in which case what are remapped ones like - or is it just the blow-by that you often get with loose "race" engines?