that is quite the loophole which should be closed TBH. I mean so long as it is legal then you do what you want.... but really if cat is required for passing an MOT then deliberately removing it and driving without one should be an offence imo.
(i mean isnt it kind of the same logic which VW used to pass their emissions tests and they got in trouble over that)
It is, if you get caught by a road traffic officer with the testing equipment, IIRC fine in the thousands and car gets impounded/defected until retested, then police have to see the MOT sheet...
There was a stage where they were quite hot on it, but usually it's a copper pulling you finding it on a loud exhaust, out of hours with no qualified DVSA agent available to come test/prove it, so they just warn you to fix it or give you a fine for a loud exhaust etc - which can be upto IIRC 110DB anyway, so they barely enforce it, and every dick with a pop and bang map Corsa to a financed DSG Golf has flames/loud exhausts these days, and despite this no police seem to bother.
In reality though, most people do just refit it for the MOT to pass. Cat's are stupid expensive and always fail, no one wants to spend thousands replacing them, and it restricts power when tuning them.
For example, a Honda Jazz, is quite often stolen/has their cat nicked/quick and easy to cut it off, because they cost something stupid like £1800+vat my mate at Honda told me, which is why so many are sold as mot fail or with a bent MOT/no cat/cheap cat off ebay that'll barely pass 1 MOT, it's hilarious of all the cars that could have a highly valuable cat, that it's a Jazz.
Regarding insurance, you can legit declare a decat along with the rest of the exhaust, and usually if you have exhaust it doesn't matter what it is, for example, I have manifold to backbox full custom stainless, and when I was explaining it was a aftermarket manifold as well, they just stopped me and said "yeah that's fine if we've got an exhaust listed, it covers it manifold all the way back!"
The same as you can legit have as a non airbag steering wheel in an airbag steering wheel car, just refit it for MOTs. I do this on most of my cars due to being a giant and most cars have massive steering wheels that literally stop my legs being able to fit or ram them so far apart I nearly pop my hips out, to the point I get cramp/pins and needles in my clutch foot/under my thigh etc and a dead arse, and the right leg ends up being smashed into the door card and causing the same pain, so I run a smaller aftermarket wheel with an extended boss kit, to bring it away from my legs and give me a better than factory driving position.
The easiest way with any modified car is to just keep anything stock you need to pass an MOT and refit it, then take it off, I usually disable ABS/ASC on my old cars because it's nearly killed me in bad weather denying me of brakes, so I just put the fuses back in for the MOT and the system is active, then remove them afterwards - however I also do tell my insurance I have an ABS delete, and I always fit bigger brake kits to all my cars, again declared, which require minimal input to stop very well, and I just modulate the peddle if needed simulating ABS as required. Easy.
(i mean isnt it kind of the same logic which VW used to pass their emissions tests and they got in trouble over that)
Pretty sure they used a trick with the fuel map, which made it make less power/better emissions, so the car would know if it's being held at XYZ revs for the amount of time required in the variation stationary and time used for the emissions test, that it would go into that different fuel map and thus pass a test - pretty sure that was how it was done wasn't it
@JonRGV250 ?
Similar to how you get a valet key when buying a car - which puts it in a limp'ish mode so no one you hand the car over to, be it a mechanic/someone to park it etc etc can abuse it.
