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2018 Q plate and MOT emissions...
furryeggs - 24/5/19 at 08:43 PM

My tiger passed itís emissions at IVA with my current exhaust and CAT. I am in the process of fitting a new exhaust and am thinking of ditching the CAT... When the MOT comes round in a couple of years am I going to have to pass the same emissions level.

2.0 zetec (2000) on throttle bodies and Emerald ECU

avagolen - 24/5/19 at 08:52 PM

Historically Q plates have only been tested for visible smoke. My car was IVA'd as 1995 pre cat system and given an age related plate. Last year the tester did not put it on the analyser, but this year he did as he said they are getting tighter on the emmisions. My V5 does not mention the emmisions on the page with all the vehicle specifications, but on the front page at the bottom, there is a note which cannot be changed that states the emmisions. I would closely check your V5 to see if there is any reference to emmisions and be aware that they might change the recommendations and stick to them.

theconrodkid - 25/5/19 at 08:03 AM

a lot of testing stations dont have a clue about imports / historic / Q plates so best to find somewhere that does or you could end up with a fail.
as above, Q USED to be a visual only

sdh2903 - 25/5/19 at 08:10 AM

Latest q plates get tested at the engine year levels now. Usually written on the v5.

Only if no limits quoted on the v5 does it get visual smoke only.

big_wasa - 25/5/19 at 08:33 AM

I got told at my last mot, if I change the engine and itís obviously different to the last they will base the emissions on the engines age.

furryeggs - 25/5/19 at 09:27 AM

Iíll keep the cat then...

SteveWalker - 25/5/19 at 10:00 AM

Originally posted by big_wasa
I got told at my last mot, if I change the engine and itís obviously different to the last they will base the emissions on the engines age.

The MOT testing manual seems to say that he is wrong.

"You must test kit cars or amateur built vehicles to the limits in the vehicle's registration document (V5c). If the V5c doesn't show any limits, you must test it to the limits of the engine fitted at the time of the SVA or IVA test."


"For emissions purposes only you should treat the following as first used before 1 August 1975:
kit cars and amateur built vehicles first used before 1 August 1998
Wankel rotary engined vehicles first used before 1 August 1987
Q plated vehicles"

But the 2019 additional notes don't seem to mention Q plates - although they don't seem to cancel the existing text either.

[Edited on 25/5/19 by SteveWalker]

A further look seems to show that the two sections quoted above still remain part of the manual.

[Edited on 25/5/19 by SteveWalker]

chillis - 27/5/19 at 11:34 AM

Whilst its not part of the MOT test yet, it is coming.
The MOT emissions will relate much more to the engine rather than the chassis, so if your car Q plate or othetwise was visible smoke when registered and the engine remains the same then it will still be visible smoke but if you fit a more modern engine then the MOT emissions will change to those of the engine you have fitted. Further this is not retrospective in so far as if you fit a visible smoke engine in place of a cat engine then you will still need to meet cat emissions for the MOT.
Its mainly aimed at the custom car boys fitting modern engines into old cars.