The MOT test uses an exhaust gas analyser - if the numbers are within the legal limit, nobody will check the details of the cat. Is there any evidence that the car has failed before with this cat?

 

Yes the last MOT it failed and was passed a couple of days later the main reason of asked is I have only recently bought the car from a dealer and was not made aware it was even fitted and obviously now wondering if it will pass it’s MOT next year

 

Sounds like a borderline cat. I'd go back to the dealer and get them to put a legal/approved cat back on.

 

I am currently going through trying to return the car to them honestly as the car was miss sold it stated it had a remap little did I know it was stage 2 (probably also not helping) also what year did the GPF start one these cars?

 

Hi everyone

I have recently purchased a a gti with a sports car fitted to it and the owner before me got in touch and told me that the car would need to be hot for it to pass a mot.

upon doing some research it turns out that their actually inst a road legal sports cat available on the market and non of them are EC approved from what i can see.

so my question is how are people getting on with getting it through a mot and is their actually a road legal one available on the market anywhere ?

I have a stage 2 sports cat GTI, and it passes MOT with flying colours (I'm not even joking when I say this, it actually passes with lower emissions than when it had the stock system). Like the seller said it does need to be hot though, all that means is that you want to drive it a bit before the test, ideally 3k+ rpm. If I were you, definetely keep it at stage 2, its a night and day difference between stock and stage 2, even compared to stage 1.

 

The dealer sold you a pup so return it to get your money back or fit a standard exhaust - was the MoT carried out by the dealer? - also you have to tell your insurance about the stage two and i bet that will be expensive, best just to return it for a refund and find a standard GTI then remap it if you want to

 

Gonna chime in on the insurance stuff, it’s a bit silly based on my experience when getting quotes for mine. Power mods hardly affected the price. Stock was £1.1k (crap postcode and near London), and with power mods including Stage 2, it was about £1.3k.

But when I added coilovers, for some inexplicable reason, I started getting quotes around £3.4k+ (ended up going with a specialist that got it down to £1.9k). So I wouldn’t worry too much about getting crazy expensive quotes for a Stage 2 car.

 

It's a misconception that as long as the car passes the emissions test, it will pass the MOT. Testers are also required to visually check for any modification to original emissions control equipment. Any obvious change should fail the MOT:

 

Surely if the OEM emissions control equipment has been replaced by equivalent equipment that has the same function and effect then there is no problem no matter whether it’s the same standard gas flow as the original or a higher flow ‘sports’ arrangement. Defect reference (a) is perhaps more aimed at the equipment being modified to cheat the results or other equipment like valved bypasses. If taken literally that wording suggests any modification of the exhaust system regarding emissions equipment is not legal which is not the case (yet).

 

And anyway, what constitutes "obviously modified" for a cat, in the eyes of a tester?
I suspect if it looks like a cat, looks like it's working, with 02 sensors in place, then they only go on emissions (as well as the usual possible failures). I think this is pedantic hair-splitting - the real issue is that the OP was sold a car by a dodgy dealer which had been modded by some kind of kludger "expert".

 

So does a "sports" cat still function as well as a standard cat? If so, why should the dealer offer a refund?

 

MOT fail for one reason. The drive to the test station should be enough to get the cat functional.
On the other hand, this is a good reason to not buy modded cars, and if you know the risks, like emissions failure, I guess that's fine. Caveat emptor.

 

As always the drive to the MOT appointment should include a gentle and prolonged warmup followed by an intense Italian tuneup.

For perhaps the last almost 30 years I’ve watched almost all of my cars while the inspection takes place but also I’ve taken most of them to a tester I know and can trust.

It’s also reassuring to know that the testers are watched from afar to weed out fraudulent activity, 10 or 15 years ago a branch of a large chain in Newbury was spotted to be failing many cars for leaking shock absorbers, a subsequent sting operation proved that WD40 or similar was being used to falsely fail cars and generate a bit of Kwik business Fit-ting replacements.

 

I had an MOT a couple of months ago. A 1.5 mile trip from overnight cold to the test station. And yet, readings as close to zero as you are likely to get with a petrol car. I've been MOT-ing cars with cats since they first existed in the UK and never got close to an emissions issue, all on OEM original cats, and with no Italian tuneups. I'm wondering if it's possible that the OP's car had a seriously sub-standard cat, or incorrect fuelling setup, or was burning oil, any of which can produce a fail. Who knows the provenance of a car not modded by oneself?

 

Talking of zero or near zero emissions readings reminded me of an MOT test on our turbo diesel Fiat Multipla over 10 years ago, at a Halfords Autocentre. I couldn't believe my eyes when I observed the tester do the emissions test with the car still on the ramp and the probe lying on the ground.

Apart from that, the test mainly comprised them wandering slowly around under the car doing a purely visual check with aid of a torch. To be fair, the car was in tip top condition, so should have passed, but I still felt cheated out of my £30.

I looked into reporting the test to VOSA, but the only options were to appeal a fail or to appeal a pass, neither of which were relevant

 

One of my Sevens 17 years ago failed emissions testing (not at my usual mot place), not by much but a fail nonetheless, the guy tried again still didn’t pass, it was a mint car, he liked the car and said it was so nice he couldn’t fail it and thus the probe ended up on the floor and miraculously it passed.
This was the same place that did some suspension work on my Passat and didn’t do up one of the lower front wishbone rear pivot bolts (not even finger tight, just a few threads engaged), never used them again after that.

Reading up on catalysts it seems Sports cats have fewer cells to aid gas flow and provide less of a restriction and it is said that they can prove marginal in certain conditions, getting them hot seems to be key to extracting their best performance.

 

I can see only one reason for a "sports cat" to be marginal on emissions. I assume such a cat is intended to be less restrictive than the OEM one, so surely it's a design issue, where they have chosen to save costs. You'd think a 2 litre car would need a cat that can handle twice the exhaust gas volume of a 1 litre car, and yet a 2 litre car should pass emissions and, at the same time, not be restrictive. So it can be done...
I think when you see the word "sports" for a car part, it sometimes just means "higher price for less, because we saw you coming", like when you see words like "audiophile" used with stereo kit, or "tonewood" on a guitar....

 

Yeah, terrifying insurance costs there, struggling to imagine them tbh. I've toyed with the idea of a sports cat and accompanying tune but it's clearly not for the nervous owner. Insurance and MoT are the problems. If the DVSA ever became involved (not sure how they might) presumably they'd just flop back against the bit that e-up has already quoted, I only see adherence to this stuff becoming stricter as we move along. Be interesting to find out how the OP gets on or what he decides to do.

 

Yes, judging by some of the noise and popping & banging going on in and around town centres of an evening I can see a TuV style approval system eventually becoming the thing for modified parts, in some ways I’m surprised it hasn’t already happened. The small minority straight piping and de-catting Lambo’s and the like will ruin it for everyone due to their ridiculous loudness.