Scion developed rotten egg odor inside car

[grandspan]

2009 Scion XD with 25,000 miles

Driving our daughters car yesterday there was the very bad odor of rotten eggs/sulphur inside the car especially noticeable at red lights and stops. Car is not showing any "check engine" light.

I know that some might say that this is a bad catalytic converter but I also know that I need to check a couple of other things first. I only gave a quick peek under the hood last night because it was late and cold outside.

I am going to check the air filter which I think was never replaced. No odor appears to coming from the battery area. The gas tank was low and she did fill the tank earlier in the day and the different brand of gas could be the cause.

Anyone else have experience with this? Any other suggestions. I know emissions is covered by the warranty but going to my dealer is the last thing I want to do. I regret ever doing any business with them.

[cerara]

we have a fleet of about 100 pick up trucks at work. several of them don't get run hard, idle too much and stink like rotten eggs. Its always been catalytic converter. Like you said, an over charging battery can get stinky, but that always smells a little different than rotten eggs (to my nose).

good luck.

[ukrbyk]

cat. battery does not smell of rotten eggs. go to Midas and ask them to perform complimentary air flow check on cat. 5 minute job.

[bob22]

Try changing brand of gas; could be something in the mix/batch generating sulfides in exhaust.

[frankiee]

If I remember right the rotton egg smell is from a rich mixture and the cat not being able to complete the reactions it is designed for.
After a time the cat will start overheating and melting the catylist material within which makes the reaction worse and the temperatures higher.
When the backflow from the exhaust rises then a bunch of new problems develop.
I would install a ``test pipe`` and have the air/fuel ratio checked

[bob22]

Wouldn't you think a 2009 car's engine management system would turn on a check engine light for an overly rich condition?

[frankiee]

The long term fuel trim vs the short term fuel trim can be out quite a way before throwing a code. I think 30 % depending on vehicle.And if it was the O2 sensor being the problem the computer would have no reference to know there is a problem. It would just adjust the fuel ratio to what it sees. Even in error.
I think the best way to know is to have the ratio checked.

[grandspan]

I forgot to update this sooner.

We let the fuel tank run down to less than half and filled it. Changed the engine air filter -which had some build up in it - and all seems normal, no more odor.

Also replaced cabin filter while I was at it.