Trevorevans Posted December 29, 2011 Share Posted December 29, 2011 I've had some different opinions on this subject from friends that work as mechanics or fitters so I want to run two questions past you guys aswell, 1. If I fit a decat pipe to my Disco will I get any real benifits power/economy wise?. Bearing in mind that there doesn't seem to be any issues with the existing cat and I don't consider a 3bhp and/or a 1-2mpg increase to really be worth the effort untill the cat does actually give up and then it would not only be for those savings it would be for saving on the buying a cat itself. 2. If I do decat then will it fail the new incoming MOT regulations as I have heard that any particulate filters or such that were fitted as standard to the vehicle being tested must be present at the time of test. Quote Link to comment Share on other sites More sharing options...
dave t Posted December 30, 2011 Share Posted December 30, 2011 I have just decatted mine at 90k miles I read that landrover say they should be changed at 100k anyway (I think its in the rave manual) I noticed more torque and a bit more top end speed Talked to my local mot guy and he said that some disco 300 tdis were fitted with cats and some were not, mines 1995, evidently it doesnt specify which were fitted so its not in the test, so he says!! HTH Dave Quote Link to comment Share on other sites More sharing options...
mikeyb13 Posted December 30, 2011 Share Posted December 30, 2011 Catalytic converters were made mandatory in the UK for all new cars from 1st January 1993 and the new mot guide states that a cat missing when it was fitted as standard is reason for rejection Quote Link to comment Share on other sites More sharing options...
dave t Posted December 30, 2011 Share Posted December 30, 2011 Catalytic converters were made mandatory in the UK for all new cars from 1st January 1993 and the new mot guide states that a cat missing when it was fitted as standard is reason for rejection True but isnt that for petrol engines, diesels dont have cats they have particulate filters. My year 2000 td5 came out the factory without a particulate filter, my 1995 300 tdi appears to have had one factory fitted!!! Quote Link to comment Share on other sites More sharing options...
muddy Posted December 30, 2011 Share Posted December 30, 2011 Arnt CATs and DPFs different things? The DPF has only just been fitted to 2.2 defenders, 2.5 ones have a CAT. Quote Link to comment Share on other sites More sharing options...
mikeyb13 Posted December 30, 2011 Share Posted December 30, 2011 Just had a quick read in the new guide and it says that if the vehicle qualifies for a full cat test it must have one fitted, but diesels have a smoke test not an emissions test so I would say the changes dont affect diesels. Quote Link to comment Share on other sites More sharing options...
dave t Posted December 30, 2011 Share Posted December 30, 2011 Just had a quick read in the new guide and it says that if the vehicle qualifies for a full cat test it must have one fitted, but diesels have a smoke test not an emissions test so I would say the changes dont affect diesels. yes thats what my mot guy said, hope hes right ) Quote Link to comment Share on other sites More sharing options...
mikeyb13 Posted December 30, 2011 Share Posted December 30, 2011 This is the page from the new manual being released 1/1/2012 Quote Link to comment Share on other sites More sharing options...
teabag Posted December 31, 2011 Share Posted December 31, 2011 Arnt CATs and DPFs different things? The DPF has only just been fitted to 2.2 defenders, 2.5 ones have a CAT. As shown in January issue of LRO and arn't they a big lump LRO do say that DPFs have also been fitted to the RR RRS for some time didn't read all of it so maybe the D4 also. I did read about Regeneration of a DPF bit so there must be info on that in the owners handbook if you have a DPF fitted. Quote Link to comment Share on other sites More sharing options...
teabag Posted December 31, 2011 Share Posted December 31, 2011 True but isnt that for petrol engines, diesels dont have cats they have particulate filters. My year 2000 td5 came out the factory without a particulate filter, my 1995 300 tdi appears to have had one factory fitted!!! Diesels do have cats as they also have CO and HC emissions at present they are not tested in the UK, lots of info on that on the www. Quote Link to comment Share on other sites More sharing options...
92.9 Posted January 15, 2012 Share Posted January 15, 2012 Due to the new MOT regulations I have just spent about two hours reading up on the catalytic converter removal issue for Land Rovers (in my case a 1996 300Tdi Discovery), but I am still none the wiser. I have read a number of contradictory statements of 'fact' from people claiming to be suitably qualified to make such statements, but they can't all be right. I can understand the requirement for there to be a catalytic converter present in order to pass the MOT, if one was fitted originally. That's pretty simple. If that's the case then it's an immediate fail for everyone who has fitted a 'de-cat' downpipe to their Discovery that originally had a catalytic converter. So, is this the case, or not? I'm not sure if it is the case as people have been claiming that a diesel doesn't have a catalytic converter as it's actually a diesel particulate filter and therefore isn't subject to a full cat test. They deny that the requirement for a catalytic converter to be present actually comes into it at all as it is obviated before that point. They go on to point out the wording of the regulations and how this is the case. Conversely, others say that you still have to have a catalytic converter fitted regardless of the wording of the regulations. Then someone says that the 'cat' (on a 300Tdi) is actually a catalytic converter, rather than a diesel particulate filter. Someone else then says it's a cat, but part of it is also a diesel particulate filter. None of this actually goes any way towards stating categorically whether everyone who has removed the cat from their 300Tdi Discovery will end up with it failing the MOT. So, does anyone actually know for sure whether a 300Tdi Discovery, that was originally fitted with what is commonly referred to as a cat, and has since had it removed, will actually pass or fail the MOT under the new regulations? I'm trying to find out exactly what the official situation is, rather than finding out that Dave at the garage down the road says not to worry about it and he'll pass it if you take it there. I'm now also interested to know exactly what it is that my Discovery has fitted, that looks like a catalytic converter. Is it a cat, a particulate filter, or a cat and particulate filter combined? Tonight I've read in various places that it's all or either of those. Thanks if you can throw some light on this utterly ridiculous situation. Quote Link to comment Share on other sites More sharing options...
mikeyb13 Posted January 15, 2012 Share Posted January 15, 2012 Diesel vehicles are not subject to a full emmissions test therefore do not require a cat to be present for mot even if it was fitted when manufactured. Quote Link to comment Share on other sites More sharing options...
Steve King Posted January 15, 2012 Share Posted January 15, 2012 My TD5 had an MOT last week and the towing electrical connectors were not tested, but the guy did give the tow bar mounting a quick wiggle!!! Quote Link to comment Share on other sites More sharing options...
mikeyb13 Posted January 16, 2012 Share Posted January 16, 2012 Only a 13 pin socket needs the electrics testing. A 7 pin socket only needs checking for condition and security Quote Link to comment Share on other sites More sharing options...
karlo Posted January 16, 2012 Share Posted January 16, 2012 MOT'ed mine last Thursday and he never mentioned about the Cat or the egr being removed, I take it year after year to the same place, he knows the car and all the mods which I have done. Quote Link to comment Share on other sites More sharing options...
BigP Posted January 17, 2012 Share Posted January 17, 2012 Got my MOT yesterday (passed first time) & my egr is blanked off. Mentioned about removing down pipe soon & was told to watch out as police were issuing Subaru drivers spot fines for missing cats. When I said I didn't think it was part of the test I was told not to make him any the wiser if I go ahead & remove it? Quote Link to comment Share on other sites More sharing options...
mikeyb13 Posted January 18, 2012 Share Posted January 18, 2012 Mot regs and police regs are 2 different things. On spark ignition vehicles that need a full emissions test need a visual check for a fitted cat, if its not there it fails. Compression ignition vehicles have a smoke density test not a full emissions test therefore do not require a check for the cat. The mot guide method of inspection doesnt even mention a cat in the compression ignition emission section therefore its not a testable item. Quote Link to comment Share on other sites More sharing options...
davyd8899 Posted January 19, 2012 Share Posted January 19, 2012 my 300tdi was bought with the cat removed, flew though MOT no problem Quote Link to comment Share on other sites More sharing options...
teabag Posted January 20, 2012 Share Posted January 20, 2012 Lets hope they don't start doing a "full emissions test " on diesels as they do in some other countries, no flying through the MOTs then. Quote Link to comment Share on other sites More sharing options...
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