Alfa Romeo Forum banner

1 - 20 of 51 Posts

·
Registered
Joined
·
30,074 Posts
What have they changed
New rule for the UK MOT this year is that if the car should have a Cat (which is all Petrols after 1992) then it needs a Cat for the MOT even if it somehow managed to pass the emissions test without one in the past.
 

·
Registered
Joined
·
30,074 Posts
Very easy to see if the pre-Cats are there or not, but the real question is if you need them or if the main Cat will be enough.
I expect the main (VERY visible) Cat under the car will be enough to keep them happy.
 

·
Registered
Joined
·
30,074 Posts
knew the main was verry visable mine in the shed.lol was hoping to get pre-cats done in next couple of weeks but think i might wait & see how others get on with m.o.t
It may only be an advisory until April anyway.
 

·
Registered
Joined
·
801 Posts
Would the tester know it's supposed to have four? I'd expect not unless they're told or are an enthusiast. They'll just see the two under the car and think sweet, they look like cats.
 

·
Registered
Joined
·
681 Posts
If you have the heat shields on the manifolds and your under tray you should be fine as nothing is allowed to be removed.
All warning lights are now failures aswell as inner cv boots and split or missing dust covers from balljoints and a number of other things that I can't remember ! Guess I better read my special notices again
 

·
Registered
Joined
·
3,118 Posts
Missing dust cover from my upper arm balljoint was an advisory on mine a few days ago. They definately upped the anty it normally sails through but they failed it on a few bulbs etc, replaced all for nothing and passed. Think they want to start showing fails for statistics.
 

·
AO Car Of The Year Winner 2015
Joined
·
3,202 Posts
Week ago I passed emission test with my CF2 GTA on standard ECU map. The results were perfect. I have here the protocols from 2010 when I still had the CF3 pre cats and from last week with CF2 manifolds.

Idle values:

Carbon oxide (%)
CF3 0,001
CF2 0,015
(limit to pass the test 0,5)

Hydrocarbons (ppm)
CF3 5
CF2 14
(limit to pass the test 100)



Values at 3000rpm:

Carbon oxide (%)
CF3 0,003
CF2 0,059
(limit to pass the test 0,3)

lambda value
CF3 1,018
CF2 1,01
(lamda range to pass 0,97-1,03)


This means that in my case both the CO and hydrocarbons (unburnt fuel) have increased, but still very far away from to values to fail the test. I am not sure if the emission measurement is standardized across EU or not, but limits apply to the emmisions tests in Slovakia, UK might be different, no idea.
 

·
Registered
Joined
·
37,751 Posts
I am pretty sure the pre-cats are only there to reduce emissions until the main cat gets up to temperature.

As long as the car is hot when they test it then it will pass fine. And as long as there is a cat visible under the car (Or something that looks like a CAT ;)) that should be fine as well.
 

·
AO Car Of The Year Winner 2015
Joined
·
3,202 Posts
I am pretty sure the pre-cats are only there to reduce emissions until the main cat gets up to temperature.

As long as the car is hot when they test it then it will pass fine. And as long as there is a cat visible under the car (Or something that looks like a CAT ;)) that should be fine as well.
Exactly. We needed to hold the engine in 3-4k rpm for about 30 second for the cats to heat up and than the results were achieved. Idle values were measured after this, when the cats were still hot. Because when the car idles for 5 min the cats also cool down and the results are not optimal.

My TS with 2 precats removed and main cat replaced with 200cpi HJS passes emission tests as well, but it really needs some heat up.
 

·
Premium Member
Joined
·
19,119 Posts
If you have the heat shields on the manifolds and your under tray you should be fine as nothing is allowed to be removed.
Shields or not you can see the back manafold from underneath very clearly. If they want to be dicks about it they can. :(
 
1 - 20 of 51 Posts
Top