Hey all, first post here so bear with me. I own a 2019 IS300 AWD currently just under 40k km. Weather just warmed up recently so went for a long drive on the highway with the windows down for the first time this season. Noticed a rotten egg/sulphur smell when merging and going open throttle on multiple occasions. Confirmed the fart smell wasn't the passengers and noticed it was only after acceleration. A bit of research online indicates problems with the cat converter, some sources say this is normal and has to do with that batch of fuel. I cant seem to find many sources with newer models involved so anything helps.

 

Welcome.

I've owned 3 different 3rd-gen ISes at this point, and all three have exhibited strange smells on full-throttle acceleration. The sulfur smell is usually because the engine is running rich - which is being done on purpose when you're at full throttle. Both my 2016 IS 300 AWD and my 2021 IS 350 RWD had this smell.

If it's happening all the time, even on moderate acceleration, you are probably having catalytic converter issues, but I don't think that's a big problem on these cars.

 

Are things like catalytic converters covered under the bumper/bumper warranty? Genuinely curious, not being snide.

 

It’s covered under the Emissions Control System warranty.
Federally, that’s 8 years / 80000 miles, unless you live in California, you’re special, you get 7 years / 70000 miles.

 

Just get catless headers and problem solved