RetroRob Posted March 14, 2023 Share Posted March 14, 2023 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 2014Thanks Rob Link to comment Share on other sites More sharing options...
Dixa1225 Posted March 14, 2023 Share Posted March 14, 2023 You will need to fit the cat to pass the emissions test. Link to comment Share on other sites More sharing options...
AMBO Posted March 15, 2023 Share Posted March 15, 2023 Depends on how bothered your MOT tester is... Link to comment Share on other sites More sharing options...
Roger Ford Posted March 15, 2023 Share Posted March 15, 2023 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. Link to comment Share on other sites More sharing options...
Benton Posted March 15, 2023 Share Posted March 15, 2023 Just for awareness..... Link to comment Share on other sites More sharing options...
Billy.Whizz Posted March 15, 2023 Share Posted March 15, 2023 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? Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted March 15, 2023 Area Representative Share Posted March 15, 2023 Just put it back. What's the problem? Link to comment Share on other sites More sharing options...
John Vine Posted March 15, 2023 Share Posted March 15, 2023 #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 Link to comment Share on other sites More sharing options...
7 wonders of the world Posted March 15, 2023 Share Posted March 15, 2023 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 ! Link to comment Share on other sites More sharing options...
RetroRob Posted March 16, 2023 Author Share Posted March 16, 2023 #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. Link to comment Share on other sites More sharing options...
John Vine Posted March 17, 2023 Share Posted March 17, 2023 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 Link to comment Share on other sites More sharing options...
Area Representative Geoff Brown Posted March 17, 2023 Area Representative Share Posted March 17, 2023 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 ! Link to comment Share on other sites More sharing options...
John Vine Posted March 17, 2023 Share Posted March 17, 2023 #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 carsKit 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 Link to comment Share on other sites More sharing options...
RetroRob Posted March 17, 2023 Author Share Posted March 17, 2023 Yes, it will be its first MOT with 2 miles on the clock.Ok, I will sort it out.Thanks. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted March 17, 2023 Share Posted March 17, 2023 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: Link to comment Share on other sites More sharing options...
Beagler Posted March 17, 2023 Share Posted March 17, 2023 #5 by Benton makes it clear. Sad that people are willing to flout the law. Link to comment Share on other sites More sharing options...
ScottR400D Posted March 17, 2023 Share Posted March 17, 2023 #16 who are you accusing of "flouting the law" then? Link to comment Share on other sites More sharing options...
Beagler Posted March 17, 2023 Share Posted March 17, 2023 Any one who breaks it Link to comment Share on other sites More sharing options...
ScottR400D Posted March 17, 2023 Share Posted March 17, 2023 Are people breaking it? Link to comment Share on other sites More sharing options...
John Vine Posted March 18, 2023 Share Posted March 18, 2023 #16: Sad that people are willing to flout the law.#18: Any one who breaks itOut 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 Link to comment Share on other sites More sharing options...
Area Representative Golf Juliet Tango Posted March 18, 2023 Area Representative Share Posted March 18, 2023 I have broken the law by speeding. I have the (expired) points to prove it. Link to comment Share on other sites More sharing options...
ScottR400D Posted March 18, 2023 Share Posted March 18, 2023 Yes, but were you 'flouting' the law?? Link to comment Share on other sites More sharing options...
John Vine Posted March 18, 2023 Share Posted March 18, 2023 flout (vt): to intentionally disobey a rule or lawWell, 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 Link to comment Share on other sites More sharing options...
JP Posted March 19, 2023 Share Posted March 19, 2023 #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! Link to comment Share on other sites More sharing options...
John Vine Posted March 19, 2023 Share Posted March 19, 2023 #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 1998If your car was first used on or after 1 Aug 1998, the following applies:Kit carsKit 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 Link to comment Share on other sites More sharing options...
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