panda_ek9

iTrader: (6)

Hey, i really am stumped about this, its a 09 is350, the car drives great in all conditions, but when ever i step on gas and the car downshifts a strange odor comes from the transmission, (in my opinion), it only does this if i step on the gas and the car downshifts or if I manually downshift in sport mode, it still drives normal, but the odor comes out, I have pulled over during this time and cannot find where the smell is coming from, so Im guessing its the tranny, any thought on this?? please..

mike33

iTrader: (1)

How many miles are on the car? Is it a sulfur like smell? If so it maybe the catalytic converters.

panda_ek9

iTrader: (6)

Car has about 102k miles.. Not sure about sulfur smell since I never smelled it before.. But if it helps I've had the car in park and and reved engine but no smell.. So its only when I'm driving it on freeway...

Lqdcourage

iTrader: (1)

Mike33 is right. Could be the Cat...

Do you have any slippage and/or loss of power when you're in gear?

Is your car an auto or mt?

panda_ek9

iTrader: (6)

No slips.. No loss of power..

Gville350

iTrader: (10)

Sounds like what Mike mentioned as being a sulfur-type smell. It usually happens once, maybe twice, during an single one outing. It will happen when at WOT or in the higher rpms, as the cats are attempting to convert the expelled sulfur dioxide into a less harmful gas. The cats either are clogged or damaged, thus not allowing the gases to be converted properly.

WillK

If it smells like rotten eggs, that's a sulfur smell and most likely coming from the cats.
I've owned 4 Toyotas and now a Lexus, and every Toyota I've owned has this smell under 'hard' acceleration.
I haven't noticed it on the Lexus, but I wouldn't be surprised if it did it too...

As for the transmission smell, if your transmission smelled, that would indicate burnt fluid or clutches. You'd definitely have other symptoms if it was the transmission- slippage, poor operation, engine would rev without movement, etc...

Have you checked under the car for any leaking fluid?

xhackr

Actually, the smell comes from the cats oxidizing sulfur in the fuel, creating sulfur dioxide, not in the reduction of it, causing the smell.

If the smell is like rotten eggs, try changing the fuel you use as high sulfur content is a likely cause, and the easiest methodology to try. Give it at least a full tank and don't use any additives before deciding.

panda_ek9

iTrader: (6)

Well I assumed it was coming from transmission because I have had the car in park and reved for a good amount of time and no smell.. So my guess is it comes out when the car downshifts