Modern Vespa

Significant exhaust change in Euro5. Is that a CAT in the manifold and is there also one in the silencer?

Maybe if you intend to buy a GTS soon-ish, make sure you get one before the Euro 5 is imported into your country ...


Edit: the lambda is also a different part number.

Very interesting Steelbytes. And how do you differentiate a euro 4 from a 5 externally. Maybe those new wheels for the euro 5 only?

My Euro 3 2019 Supertech has the new wheels. Asia Pacific got the new wheels before they rest of the world

That looks suspiciously like a petrol particulate filter. I hadn't seen that on the HPE previously. It may be that Piaggio has done that in readiness for Euro 6. You must have a petrol particular filter to comply with Euro 6. However, it may just be a 'resonator' to help tune the noise (quieten it) and exhaust gas pressure pulse for better power. Anyhoo, there is a full 3 way catalyst in the silencer just the same as on previous bikes.

If it were a DPF it should be active functioning and therefore with a container of liquid or powder with consequent filling cap.
It is certainly the three-way catalyst (omnipresent on all scooters); Generally, to raise the anti-pollution standard, the ECU parameters are used, which communicating with the lambda probe tells the engine how to work.
In reality, the HPE upgrade to 24 hp was required to upgrade the Euro 5 (even 6) operation on all models that use it, the point is that you will never have the maximum declared power because the priority is given to the parameters pollution sacrificing the power.

OK, I thought not to ask, but curiosity won

Why a CAT is a bad thing in Vespa?

I do remember the stories of those challenging evap canisters installed into US Vespas, but CATs are in every bikes, don't have any impact to your ride... ?

They restrict airflow which is in general not a good thing for performance

Here is the Arrow 53536ANN exhaust for the Euro 5
https://www.arrow.it/en/assembled/1737/Piaggio-VESPA-GTS-300-HPE-2021
(pic taken from https://vespaforum.de/viewtopic.php?f=15&t=54763)

interesting to see that they include the 'bulge' in the pipe and also the usual cat that slips between the silencer and the pipe. if you check their website then you'll also see that they don't have it in their 'racing' pipe so I guess it is only for regs and doesn't help power.

You must be equipped with a dedicated gasoline filter

small note: it's not me. I don't have this

Attlla, a DPF is not a petrol particulate filer (PPF). The two are quite different and cannot be compared to each other. While a DPF can be passive (not requiring any liquid ignitable fluids) or active (requiring an ignitable fluid to raise it's temperature), a PPF is always passive and works differently to a DPF. Petrol particulates are much finer and harder carbon particles and cannot be completely reduced to ash like diesel particulates. The PPF simply catches them, burns them and holds them. Since petrol engines produces so few particulates a PPF will normally last the life of the vehicle and requires no maintenance. The engine will always produce the power the manufacturers state it will produce. I think you mean the engine will not be able to reach it's maximum potential power. For example, the HPE engine will be capable of reaching higher power without a catalyst or PPF (if indeed it is a ppf).

However the FAP / DPF in the mufflers of the sccooter are not yet; there are only three-way catalysts.
And I mean the stock mounted mufflers, in the after market ones it is between the manifold connection and the muffler

And don't forget that a DPF is a Diesel Particulate Filter and not fitted to petrol engines. What is an FAP?

Edit: just realised FAP is the French term for a DPF, but of course not fitted to a petrol engined bike.

But in fact in Italy many buy after market mufflers to open them and remove the catalyst (also the db killer) to get a little more power; the problem besides the greater pollution is the noise ... it increases a lot.
However I like the original noise and if I wanted to go faster I would have bought a more powerful scooter.

Yes, they do that over here too!

I see, so nothing Vespa specific. Thanks.

It would have been cruel for the cat ...

Hi all, I have an issue here, is there anyone can help?
I purchase gtv300 hpe 2023 which I assumed the spec is E5 as it was said everywhere in the web, apparently in my country the GTV300 2023 is still E4

I already purchase Vespa sport exhaust for E5, when I install it then the issue come up, the exhaust doesn't fit with the manifold (shorter) so there is no way to connect to silencer/muffler

The vespa sport exhaust/muffler I purchased is homologated and I saw inside there is catalytic converter inside the beginning of the muffler


Can someone help me how to use this exhaust? Will the E5 header manifold and do some mode to decat it solve my problem? Thanks

Here are some pics of it

GTV300 2023 doesn't fit Vespa Sport Exhaust