John-M 0 Posted November 8, 2006 What is the legal situation regarding cat-bypass when replacing the original exhaust system ? I have a '94 VR6 with 165k miles - and it cant be long before I need to be looking at a new system. Is the year of manufacture / registration the key issue ?? First post in this forum, by the way. Quote Share this post Link to post Share on other sites
DanVW 0 Posted November 8, 2006 Hi John, Welcome to the forum! :-) not sure on the legal situation regarding Cat-bypass but as far as I am aware all cars built after August 92 that where supplied with a cat must have one fitted and working at MOT time. If I am wrong here please some one step in and correct! Cheers Dan Quote Share this post Link to post Share on other sites
double-6s 0 Posted November 8, 2006 All rado VR6s came with a cat. However, if you can either find a friendly mot man who will stick his 'probe' up someone else's exhaust, or get your vr running so well that it passes the emissions without a cat, then you're laughing. Quote Share this post Link to post Share on other sites
RADO.001 0 Posted November 8, 2006 double-6s, is it really posable to pass an mot without the cat? my mot is due soon and i dont have a cat fitted :confused4: Quote Share this post Link to post Share on other sites
double-6s 0 Posted November 8, 2006 I think it is possible mate. Not sure how easy though. Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted November 9, 2006 It's a grey area this one and has been discussed many times...... If the car passes the emissions, it passes the emissions whether there is a cat there or not. There is no "Is there a cat on the car? - Yes / No" on the test sheet that I'm aware of :-) The cat burns off hydrocarbons and the emissions measures CO2 at idle when cold and CO2 at hot idle and at 3000rpm (IIRC?) and also hydros. It is possible to get the hydro levels down to permissable limits without a cat, so long as the engine isn't a physical knacker and tuned well. I like cats for the smell they make in the mornings, a nice modern smell. I hate 60s knacker petrol fumes......but the supercharger destroyed my 100 cell sport cat, don't bother with one at all is my advice! Quote Share this post Link to post Share on other sites
tug 0 Posted November 9, 2006 According to the MOT computer system, my VR doesn't have a catalytic converter! Which is handy...because it doesn't... Quote Share this post Link to post Share on other sites
RADO.001 0 Posted November 10, 2006 so should i buy a cheap cat just to be safe on the mot side of things kevHaywire? Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted November 10, 2006 It's probably an idea..... I've got a couple of cats which I have hanging around for special occasions :-) Quote Share this post Link to post Share on other sites
Neil VR6 0 Posted November 10, 2006 I think there are lots of forum members around the country with "pool" cats that get passed around at MOT time ;) Quote Share this post Link to post Share on other sites
Johnboy98 0 Posted November 10, 2006 My guy passes my car without a cat but my Hydra Carbons are low cos its running on Propane. Quote Share this post Link to post Share on other sites
RADO.001 0 Posted November 11, 2006 better start lookin for a cheap cat then! Quote Share this post Link to post Share on other sites
jonnyboyo 0 Posted November 17, 2006 Yeah you will defo need a cat to pass MOT. And DanVW was right with the Aug 92 info. There is another issue tho. This being the traffic cops doing spot checks on emmisions at the roadside. Although i believe these to be very rare and certainly wouldnt put me off removing my cat, if i had one! Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted November 17, 2006 During my last MOT, it failed on the emissions (MAF was fecked) and the garage said that if my car had a Cat, it might have passed easily, but they passed it anyway!!. Afterwards, I asked them what they thought the Milltek Sport cat was that was fitted at the time!! :lol: Numptys! You can smell exhaust fumes that have passed through a cat a mile off, so they must have had no sense of smell aswell as being blind! Quote Share this post Link to post Share on other sites
Johnboy98 0 Posted November 17, 2006 Bugger...mine has just failed on the PPM's, think the lambda is goosed! Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted November 17, 2006 CO or Hydros? Quote Share this post Link to post Share on other sites
Johnboy98 0 Posted November 17, 2006 CO's mate Quote Share this post Link to post Share on other sites
Kevin Bacon 5 Posted November 17, 2006 Could be MAF or Lambda as you say... I swear they've reduced the CO margin older cars have. Mine never used to have a problem with emissions at all but now it's always borderline since the MOT when computerised..... Quote Share this post Link to post Share on other sites
PeteC 0 Posted November 19, 2006 VR's fitted as original in vehicles (ie not a transplant) should by law have a CAT fitted for the MOT, but the irony is that the emmissions levels for those years are not as high as for new cars today so in fact any VR which is running corectly will pass anyway even if the CAT is shot ! As a result of this the pressence of the cat can be often overlooked as long as the numbers are OK. This means there are lots of options in practice depending on who will test the car. No CAT, Cat with the insides taken out etc. As far as I know it's not against the law to drive the car on the road without a CAT but u need to watch the insurance situation as they will look for any excuse not to cough. Removing the CAT would definately be classed as a modification ! Quote Share this post Link to post Share on other sites
