So here is my issue. I have a new 2023 Infiniti Qx60 with 6,000km. Right from the start when I drive on the highway I smell a rotten egg smell in the cabin and vents are all turned off. This is where it's gets tricky, this only happens after driving in the city for a few days and then entering the highway. So for example for 5 days driving in the city no rotten egg smell but once I enter the highway it happens once and it's strong but then goes away. Mechanic had my car for a week and took it on the highway and was never able to reproduce the problem but once I got it back and drove it the city and took it back on the highway smell came back. Any ideas? They are Stumped.
That rotten egg smell is your catalytic converter burning up the gas fumes leaving the exhaust manifold. It's a new car, so take it to the dealer and have him fix it "under warranty".
Did you check the AC filter?
This happens with everything turned off, no AC or heat are running.
That rotten egg smell is your catalytic converter
rotten egg smell is hydrogen sulfide. It can come from malfunctioning batteries too (which contain sulfuric acid).
Either way, it shouldn't be happening to a new vehicle.
