De-cat pipes

So I’ve been scouring the internet for a suitable upgrade on the Fazer and I’ve got my eyes on a few bikes. One of which is the Duke 690, but some of the used ones have aftermarket exhausts with de-cat pipes on. Now when I’ve looked at exhaust sites they all say “not for road use” etc. on the straight through systems, but do the police/MOT folks/DVLA run around checking if you’ve got a cat (not Aceman’s) on your bike?

I would imagine because the bikes with decats would no longer be meeting the required emissions

the exhaust companies would be doing an ass covering exercise

both my bikes are “decatted” and have never had problems passing an mot

if decatted the bikes would need to be correctly tuned

+1 never had an issue with the police or MOT centre

Many bikes have several cats, e.g. my R6 has 3… in downpipes, collector box and silencer can.

Changing just the silencer for a de-cat slip-on may make little difference to the mapping.

But if the Duke has been completely de-catted it should have been, as Wise says, re-mapped and that may require a power commander or similar on many bikes, not sure about that Duke.

Not a problem with sound regs or emissions in UK though.

Ok cool. I had a feeling it must be overlooked by authorities, otherwise there’s a shitload of people switching back to the stock exhaust every year at MOT time.

“…but do the police/MOT folks/DVLA run around checking if you’ve got a cat (not Aceman’s) on your bike?”

Ha ha, love it :grin:

I’ve been wondering about this. Do we think, when the ULEZ comes in, they may soon after start introducing emissions tests for bikes?

They would have to do it for all motorised transport
Some nearly new of the shitboxes I’ve been sat behind Shouldn’t be on the road
Maintaince is the reason and motors tend to have better care bestowed on them

I have a ZX-6R with an Akrapovic slip on and their “decat pipe”, but I have not removed any cat at all (the wording is a complete scam). I have changed the can and removed the pre-silencer which changes the volume and more to the point, tone of the pipe. The cats (3 separate items) are in the headers and they’re welded in so they won’t be coming out until I can afford some Akra headers.

Just a heads up - things aren’t always as they seem. No worries for MOT though, just keep the baffle and put it in when you get there.