Do I need a Cat to pass the MOT?

[Stonky 62]

Hi - I have a 2b running a Ford Zetec ST170 fitted with bike carbs.

The car went through the IVA in 2003 and the emissions is stated on the V5 as CO 4.5 & HC 0.12. It was fitted with a Pinto engine at the time.

I need to fit a silencer to the exhaust manifold and I’m wondering if I need one with a Cat or if a standard non-cat unit will get me through the MOT emissions test?

Any suggestions as to where I can get one would also be much appreciated.

Any thoughts welcome!

Many thanks,

steve

[tractor]

if it was fitted with a pinto engine it will piss through the emissions test with a zetec on bike carbs if set up correctly i would tell the MOT tester its a visual smoke test only its worth a try what is the reg number on it 

[IanS]

If your V5 still states CO 4.5 & HC0.12 then this is what it should be tested to and a standard exhaust should work provided the carbs are set right.

If you want a cat than https://kitspares.co.uk/collections/exhaust/products/exhaust-silencer-repackable-zetec-with-cat  is probably a way forward.

[tractor]

i had a CO reading on my V5 for my GBS zero but because of the reg year it was a visual test only and that CO reading was for a pinto and i had an st170 with bike carbs so if you have an old reg number on it no worries 

i would say the main factor is it didnt have a cat when it was IVA so it dont need one now 

Edited August 10, 2022 by tractor

[alanrichey]

1 hour ago, Stonky 62 said:

The car went through the IVA in 2003 and the emissions is stated on the V5 as CO 4.5 & HC 0.12.

Interesting, they must have changed the units, mine was SVAd in 2008 and it states CO 0.2% & HC 200ppm.    I had it MOTd yesterday and she managed CO 0.096  and HC of 91.   A nice pass.

[tractor]

a CO of 4.5 and HC of 0.12 is very very generous because its a pinto so a zetec on bike carbs will piss it if set up correctly bike carbs are far more efficient and so is a st170 engine plus there are no re circulated vapours 

Edited August 10, 2022 by tractor

[Stonky 62]

Thanks very much for the feedback - much appreciated. Sounds like a non-cat silencer should get us through the emissions test which is good news - they’re a lot cheaper! Thanks also for the link to Kit Spares - I see they supply units with or without a cat - £200 less for the non-cat version! 
 

Tractor - it’s on an A plate. I’ll try & set up the carbs right to get it through - otherwise I’ll be making my way to a local tuner!

Alan - congrats on the MOT pass - is yours fitted with a cat to get those results? 

[alanrichey]

Yes, all the Superspecs came with a cat otherwise you didn't stand a chance of passing the HC test.   Also, I recently fitted a new lambda sensor as the one I had was getting very old, so I credit that with the good CO reading.   Superspecs have all struggled with the emissions test and since I started using my laptop to check the other Superspecs in the Club I have yet to find one that actually had a working sensor.   The sensor supplied with the kit had a life of about 2 weeks , some hadn't been wired up correctly, none of them used a screened cable to carry the signal and some were mounted facing downwards encouraging water to ingress.   It's taken me 8 years to figure it all out but I have now passed 3 emissions tests in a row,   Happy days.

[tractor]

what year is A plate 

somebody may correct me but i think 96 or 97 is when the emissions test came in so any reg before that is a visual  smoke test only 

Edited August 10, 2022 by tractor

[Stonky 62]

1983 I think- be great if it was a visual smoke test only! 

[tractor]

1983 gaw blimey guv that's a visual only all day long 

[nelmo]

My last 2 MOTs were smoke tests - on a 17 plate! One because the guy was too lazy to bother looking it up and the other because he couldn't get the sensor far enough up the exhaust to get a reading...

[alanrichey]

Mine are very keen on the emissions test.   I have to regularly remind them that my car MUST be bought up to operating temperature and left like that for a couple of minutes before they take the readings.    This time they got a bit over-enthusiastic and ran her up to such a high temperature she blew off her lower cooling hose and filled their inspection pit with boiling water/antifreeze.   Serves them right

I also learned something else about MOT tests.   In previous tests they have damaged my sump getting it onto the rollers, on one occasion ripping off the sum rguard I have fitted.  In discussion with my mechanic (an ex-MOT tester), he mentioned that if they can't get the car on the rollers because of the low ground clearance then they can do an alternative brake check called a 'tap test'.  Apparently they put a gadget called a Tapley deccelerometer into the car, drive around the block and test the deceleration produced by the brakes.   So I asked them to do that instead of the roller check and the brakes passed    This may have been common knowledge but I had never heard of it.'

Al

[IanS]

Tap test was the only test before rollers came in, some 4x4 cars have to have this test as they would need a set of rolllers front and rear to test.

0.5G for main brake 0.25G for handbrake or like my old thames van handbrake had to lock the rear wheels as empty it had no hope of 0.25G.

[emptyat]

The emissions rule is fairly clear, my 1985 Exmo is visual only, as is any kit first used before 1 August 1998.

Here is the link

MOT emission testing for kit cars (rhocar.org)

Malcolm