airtime

This happened a couple of days ago. As I was climbing up a fairly steep hill and accelerating heavily and going about 60mph for 1/4 mile, then came to a stop light, I notice a faint sulfur smell coming from the car. Is that from catalytic converter or ???? Smells goes away after normal driving and hasn't come back unless I again tried that same hill to be sure that was the cause.

Anyone??

I6turbo

iTrader: (1)

I can't answer your question for certain, but I wouldn't be at all surprised if it were the cats after an unusually hot pull. FWIW, early model GM cats used to smell like sulfur most of the time.

airtime

So is that a bad thing or normal?

LiCelsior

iTrader: (32)

pretty much normal.

GRAND_LS 4

iTrader: (2)

thats the cats for sure. Also referred to as rotten egg odor.

To be honest, i don't really remember smelling anything from the cats once the car was warmed up.

pete896

your car is only a few year old.. I don't think is your cat

I6turbo

iTrader: (1)

Nobody is saying the cat is crapped out -- just that they can produce that smell -- they (some models, at least) can do it even when new.

airtime

Its been days now and I haven't gone up that hill again. No sulfur smell at all.

I'll try that hill once more this weekend to see if it reproduce it. Maybe it's the top of the hill that smells

JRcanuck

From my experience on second GEN IS, during WOT with either the windows or the sunroof open, if you smell rotten egg gas it’s because the rear pressure flaps in the rear quarter panels are leaking. There’s a rubber flap that gets old and gets brittle an d breaks anway. And that allows exhaust gases to enter the trunk and into the interior cabin. Worth checking out. You can check their condition from under the car or through their rear trunk by removing the access panels, the right side is under the stereo amp. I had to change them in both my ‘07 IS250 and my ‘12 IS350. And just to note, I did NOT have to remove the rear bumper cover as we did it while up on a hoist. Good luck. Cheers

PN 62930-12161
ps leaking flaps are also responsible for rusting out the bottom side of the amp