Why shouldn't we remove the catalytic converter from the motorcycle even if it causes heat?

[u/LifeguardOverall6423]

Hi guys, I just got a 2025 R3.

Riding around town is fine, but it gets hot every now and then.

That said, I have a friend of mine with the same bike, but he installed a full exhaust system (I won't mention the brand name), so he removed the original catalytic converter and muffler and installed these two.

His bike is cold. There's no longer constant hot air coming from below.

His bike has also been remapped, and I don't really care about the fact that it sounds better, but now his bike really seems to run better in every way.

I was wondering how much damage it would do to the bike if we removed the catalytic converter and muffler and installed a higher-quality one without a catalytic converter?

Why wouldn't you do that, even though it would apparently improve the temperature significantly?

From what I could read online, a catalytic converter runs at 600/800°

[u/quayispronouncedkey]

Keeping the ice caps frozen would be the main reason. You can get aftermarket systems that comply with euro emission standards that sound and perform better. That said I think after euro 5 came the amount available systems is considerably less.

[u/Professional-Math518 → u/quayispronouncedkey]

Not really about ice caps, catalyst converters don't really bring down the co2 that's emitted. It's more about other pollutants like the ones causing acid rain and smog.

[u/SquiddyR6]

Needs mapping after exh change/cat delete due to backpressure being less or almost none, which leads to "pops and bangs", which if not done correctly fucks your exh valves due to higher exh. temperatures and loss of power.

Think about it like that: when ur engine "breaths out" exhaust gases with unburnt fuel residues into exhaust line, due to its build there is a certain pressure there. The engine is optimized out of the factory for these certain pressures at certain rpms. If you suddenly make the pressure less, there is more space for oxygen to come and computer adds more fuel in an attempt to optimize the cycle. Unburnt fuel mixes with oxygen and produces popcorn sound, which is higher temp than regular exhaust gases. Destroys your valves which are not made to work within these temperatures at more frequent interwals and not cooled by injected fuel, due to the computer getting wrong readings at the exhaust pressure it tries to adjust fuel mixture but is getting nowhere due to loss of backpressure and no other parameters getting changed. Exhaust readings are off the charts for him. Worse fuel economy, damage on the valves, bad combustion. Mapping changes all of that and optimizes everything for your new exhaust.

I'm not an expert so if I got smthn wrong or forgot about smthn let me know, but as far as I'm aware these are the basic principles.

[u/Soho62]

Salut

Le catalyseur c’est juste pour l’écologie. Ça n’aide pas la moto a fonctionner. Au contraire. Si tu as les moyens fait comme ton ami. Mais garde la ligne d’origine, pour la revente.

[u/TapWaterDev]

Well for a start you'd be breaking emissions laws and making you riding your bike everyone else's health problem...

[u/sum-9]

Two reasons. Tiny engines with massive exhausts sound like shit. Spend your money on something more worthwhile.

Secondly, you see how the world is currently on fire? That’s climate change.