MOT and decat

[RetroRob]

I have a Sigma 125 which is fitted with a decat pipe (sensor screwed to the decat).

I will need to get an mot as its not been in use since it was registered.

The cat came with the car in a box,  will I have to put the cat on to pass?

2012 order but got its first reg jan of 2014

Thanks Rob

 

 

[Dixa1225]

You will need to fit the cat to pass the emissions test.

[AMBO]

Depends on how bothered your MOT tester is...

[Roger Ford]

The cat will be required to pass the emissions test. However some specialist MOT places have been known to forget to insert the test pipe in the exhaust at the critical point - or indeed insert it into the wrong car's exhaust.

[Benton]

Just for awareness.....

[Billy.Whizz]

Correct me if I'm wrong but I think our cars tax class comes under vans and light goods, so does that mean we could be fined the £2500 for having a de-cat?

[Golf Juliet Tango]

Just put it back. What's the problem?

[John Vine]

#7 Just put it back. What's the problem?

Well, a significant problem for owners of Duratecs with roller-barrels is potential cat damage due to unburnt fuel on over-run. 

Apart from that, I'd agree with you.

JV

[7 wonders of the world]

its not so much the over run more the full power,, when the excess fuel  'warms the cat' to the point they will easily glow cherry red and on side exit exhausts will have blue tail flames under load, just watch the 620's on you tube, repeated exposure to this will melt the core.

closed loop conditions are normally up to circa 3k and 50-60% throttle after that your open loop..... so unless you replace yours with a race cat which offers less restriction however these may not help you meet the MOT requirement in terms of emissions, having just bought one I know this can be the case..... so I had to buy another !

[RetroRob]

#7  its not a "problem"  its a question.

The cat in the box appears unused. No sign of clamps or insertion marks.

The car came as is, never used since passing its post build test. 

I see other Caterhams with no secondary cat.

The cars are taxed as PLG not under the co2 measurement system.

Hence the question.

[John Vine]

To answer your original question ("...will I have to put the cat on to pass?"), the short answer is Yes (always assuming that the tester follows DVSA's prescribed MOT procedure).

Presumably the car would have been IVA'd prior to its 2014 registration?  If so, it would have needed a cat to pass.  Perhaps the owner simply replaced it with a decat pipe straight after?

If the car hasn't been used since 2014, I take it the planned MOT is its first?

JV

[Geoff Brown]

To fit a cat or not to fit a cat that is the question.........from previous but not recent experience some MoT Inspectors are unsure of the status of Sevens post cat fit requirement.

If the car is home built without further reference they can go straight for the 'smoke only test' irrespective of the youth of the car.

The MoT outcome depends on whether the Inspector likes Cadbury Milk Tray or not !

 

[John Vine]

#12  If the car is home built without further reference they can go straight for the 'smoke only test' irrespective of the youth of the car.

That's not been my experience, Geoff, although I have often needed to point the tester to the Emissions Standards doc (see below).  The testers I've used always start with the Basic Emissions Test (BET), and then move on to the specific Cat test should the car fail BET.   Maybe I could simplify things with some chocs!

The date after which a cat is required is clearly stated in the MOT Manual:

Kit cars

Kit cars and amateur-built vehicles first used on or after 1 August 1998 must have either Single Vehicle Approval (SVA) or Individual Vehicle Approval (IVA).

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

The engine limits are shown in the In-Service Exhaust Emission Standards for Road Vehicles --19th Edition.  Caterhams are listed on pp 23-24.  I always take a printout of those pages as I often find I need to challenge the tester's attempts to fail my Duratec for Lambda > 1.03!

JV

 

[RetroRob]

Yes, it will be its first MOT  with 2 miles on the clock.

Ok, I will sort it out.

Thanks.

[aerobod - near CYYC]

Re #13: Yes Lambda 1.03 would definitely be hard to achieve on a Duratec without a cat, John.

My car is cat-less (doesn't need one in Canada for 'Repli-kit' class of cars that mine comes under). I have set the target Lambda at idle and Throttle Site 0.0 to 0.97 to make it a bit smoother, the target Lambda at 2500 below Throttle Site 8.0 is 1.00. My fuel trims are much better (i.e lower) than the standard Caterham map, so the mapping is better optimised to the engine. This is the wideband Lambda readout with the left side of the graph mainly at idle (1000RPM for my car) and the right side just over 2500RPM:

[Beagler]

#5 by Benton makes it clear. Sad that people are willing to flout the law.

[ScottR400D]

#16 who are you accusing of "flouting the law" then?

 

[Beagler]

Any one who breaks it

[ScottR400D]

Are people breaking it?  
 

[John Vine]

#16: Sad that people are willing to flout the law.

#18:  Any one who breaks it

Out of interest, have you ever knowingly "broken the law", by which I mean any law?  If so, perhaps you'd be willing to enlighten us.

JV

[Golf Juliet Tango]

I have broken the law by speeding. I have the (expired) points to prove it.

[ScottR400D]

Yes, but were you 'flouting' the law?? 

[John Vine]

flout (vt):  to intentionally disobey a rule or law

Well, that's pretty clear.

It's probably true to say that, every time I venture out on to UK roads (in 7 or tintop), I break the law at some point by exceeding the stipulated speed limit.  Do I do it knowingly?  Yes, definitely.  Do I do it intentionally?  Hmmm... interesting distinction.

JV

[JP]

#13 - Thank you for the emissions standards document.  I've looked up my 1999 K-series and I have the date code "W". 

My original Caterham silencer with incorporated cat must be completely devoid of packing now and it looks as if I can replace it with whatever I want as I'm subject to a visible smoke test only!  When the car was on the road, I think that every MOT I had I have had to have a proper emissions test - but that seems to have been incorrect!

[John Vine]

#24:  You're welcome.  Glad it was useful.

I've looked up my 1999 K-series and I have the date code "W"

This looks like getting complicated...

"W" is the 1998 chassis year.  When was your car first registered?  Presumably 1999?

The MOT Manual says:

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

If your car was first used on or after 1 Aug 1998, the following applies:

Kit cars

Kit cars and amateur-built vehicles first used on or after 1 August 1998 must have either Single Vehicle Approval (SVA) or Individual Vehicle Approval (IVA).

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

For the "W" chassis year (1998) or earlier, I think a further complication will lie in the 6th letter of your VIN.  If it's not C or K, I suspect the "amateur-built" tag won't apply.  What is your 6th character?

Note that the DVSA guide works on chassis year, whereas the MOT Manual works on registration letter. So there's an ambiguity in the rules for registrations between 1 August and 31 December 1998.  If your first reg date falls between those dates, I reckon you could successfully argue for a visual smoke-test only.

JV