BoOsTin FD

What does this odor mean? As i was redlining my FD, my friend behind me said that the smell coming from my exhaust smelled like rotten eggs. Anybody have any idea what is causing this? It just happend once or twice i'm not sure though. I just changed oil and cleaned my spark plugs. Also, for some unknown reason the car is running a little rich at idle.

One more questions, how do i know if the O2 sensor is bad?

thanks guys

Mahjik

iTrader: (1)

I've always heard that means the cat is failing. Don't know how true that is as I've never experienced it.

BoOsTin FD

well i only have hi-flo cat which is plugged to air pump.

Mahjik

iTrader: (1)

Hi-flo's can fail too..

I did a search on Google (more information is out beyond this forum) and there were two possibilities:

1. Problem with the octane used
2. Failing catalytic converter

What octane are you running in the car? You could try a different octane rating and see if that makes a difference.

BoOsTin FD

i'm always runing 93 from the same pump that i used for 2 years.

Could my problem be the O2 sensor? What are the signs of it when it goes bad? Cause this all happend suddenly. It went rich all of a sudden and i got that smell.

911GT2

My friend bought my MX-6 that I used to have before the 7. Same rotten egg smell, it was the cat.

How new is the hi-flow?

Mahjik

iTrader: (1)

Nope, the O2 won't have anything to do with that... The only thing the O2 "might" do (with stock ECU's) is throw a code and give slightly worse gas mileage.

gohorns

maybe someone stuck an egg in your tailpipe

BoOsTin FD

I have no idea how new is the cat, however i doubt it's clogged up. Something else is acting up, as all this happend at once.

Another thing that i notice is that the car behaves kind of strange after 5500rpm. I get full boost but it seems like there is no power, it's like the redline is at 6k. It's hard to explain but, it's like i'm driving my car only on turbos after 5k.

Mahjik

iTrader: (1)

Losing power, rotten egg smell, those are pretty tell-tale signs of a clogged cat.

BoOsTin FD

Great. I'll have to try something then. I still have my original cat.

rx7will

iTrader: (6)

Either a bad cat or you air injection is not working. The cat needs air to function properly.

911GT2

Yes, for emissions purposes. But the air will flow just fine without the airmpump hooked up. I doubt that would cause the problem.

clayne

It's the cat. 99%.

Johnsrx7

Your cat is going, time for a new one most likely.

NewbernD

iTrader: (1)

Actually, the rotten egg smell has almost nothing to do with the health of your cat. It's a result of sulfur deposits in the gas that don't burn as part of combustion. They smolder in your cat. If your o2 injection was 100%, it would probably increase temps at the cat high enough to burn them off before they stink, but basically nothing's wrong. Go to a different gas station and fill up until the station you usually go to burns through its last tanker full.

Sinful7

Like the others said - it's the cat, same thing happened to me before, I had replace the cat with a straight pipe.
No emission law here

BoOsTin FD

i have the damn emissions here, Plus i used to have open exhaust on my FC and i hated it the way it smelled. SO i don't want to go do that on the fd, but i will give it a shot.

Thanks guys.

RollnDrty

There seems to be a lot of responses pointing towards the cat... But from what I have been told many times in the past is that a rotten egg smell is related to a poor/clogged fuel filter. I would change the fuel filter before replacing the cat.

David Beale

As stated earlier, it is caused by high sulpher content in the gas. Switch to a different gas (company, station, or whatever). I've had this with two different cars. Had nothing to do with the cat. It will take time to burn it out of the cat. Try different gas, and a good high speed highway trip to heat up the cat.

Bruceman

iTrader: (5)

Everyone is correct but NewbernD is most CORRECT
CAT is causing the smell but....
Sulfur from gasoline will collect in your CAT. Then when you drive the car hard with lots of wide open throttle the sulfur turns to sulfurdioxide which smells like rotten eggs.
Your Cat can't make your car run rich. That is something else.

jdhuegel1

Slap the stocker back on and see if it goes away. That way you can either confirm or eliminate it being the cat. Then start going to other places to find the culprit. It's easier to start at the place that everyone with similar experience says to... I learned that here. You can use my tools if needed.

Justin

jdhuegel1

Well, I guess it would be easier to change the gas FIRST... Then move to the CAT.

BoOsTin FD

I bought a $18 bosch o2 sensor, so i'll give that a shot see if it will help with running rich. And about the smell, I'll go to a different gas station and fill it up and i'll add that Techron Cleaner and see what's gonna happen then.

David Beale

I suspect everyone associates the sulpher smell to a bad cat. because it can build up in the cat. before it starts to smell. This takes time - and it takes time for the cat to wear out as well. So it is more likely you will get the smell about the time the cat is worn out. It is from the gas, however. The high sulpher content here in Alberta took out two O2 sensors in my Pathfinder - $200 each - thankfully on warranty. No smell yet from that vehicle. My previous "beater" started giving off so2 after 5 years or so of high sulpher gas. Cat was still ok when I sold it 3 years later (no codes from ECU).