Rotten egg smell

[RobW]

i get a sulphur or rotten egg smell when I am on the highway 130kph or 80 mph going up a hill and putting it under a load.(I took it to the dealer..ya I know better)
This started a year or so ago, it also pinged back then.
The dealer did a intake manifold clean, and then re-programed the computer to the newest software. Seemed to help a little but still had the smell. Then they changed the O2 sensor. Thought everything was okay for awhile.
Took it in for the 100k service...(Canadian) 60,000 miles...And soon after, had check engine light come on. Seems the mechanic didn't seat the plug wires down right and fouled the plugs. Well, they put in new plugs (free)and replaced my spark wires the the same time as 1 was bad. Well, I still have a rotten egg smell and not too excited to drop more money at the dealer without more info if I can.Any ideas? 5 litre V8

 

[410Fortune]

You are kidding me?
Nobody said anything to you about the cat converters?

Rotten egg smell, sulfur smell in a car means the catalyst in the cat converter (you have 4) is bad/no longer working. this is common knowlege, any mechanic worth his salt should have pointed this out to you IMO

Now with that knowledge there are things that will shorten the life of the cat converter, raw fuel is the main one, and this is caused by running rich, gas not getting burned, a bad 02 sensor, etc

 

[RobW]

Well, yes I could understand a bad cat...if it had more miles, but 60,000 miles? And don't forget, the o2 was replaced 1 1/2 years ago.Could it be because it is used mostly in the city?Doesn't get too much highway miles.

 

[410Fortune]

a cat converter can last 500 miles if its getting fuel dumped into it.

how does the truck run?
Any engine codes?

You have 4 cat converters

If you are smelling sulfur I hate to say it but its a cat converter or actual rotting eggs possible farting

 

[410Fortune]

Now with that said as you know you have 4 02 sensors, right?
two are the actual metering devices responsible for telling the computer how much 02 is in the exhaust, giving it a basis to adjust the air/fuel ratio.
the 2 after cat sensors are catalyst monitors, they will tell you with a code or light that the cat converter is not doing its job.

If you are not getting a code and the truck is running perfectly then I would suspect the aux cat converter assmbly which is down stream of the catalyst monitor 02's. These are not required for emissions, at least not in CA, they also are robbing you of some power.

it is not uncommon to get the smell early on in the stages of the cat dying, especially when some fuel gets through, say after flooring it for a bit and then having to drop RPMs and slow way down, come to stop, get off the higway, etc. So this does not mean your cat converter does not have another 60K mies in it, but I an tell you 100% the cat is whats producing that smell

 

[RobW]

Well, my wife has complained about some farting, but that's another story.
Guess it's time to check the cats and 2nd stage o2 sensors. Dam, more money out......
Up here all city vehicles have to go through "Air Care" . They test the exhausts and if you fail, you need to repair or you can't get insurance.
Thanks for the help.

 

[Glacier991]

The following explanation is not mine, but out of my archives - on the WHY of the rotten egg smell:

"The sulphur smell from the exhaust, is actually caused by running the engine/cat convertor slightly lean for long periods and then running under a rich condition (ie going up a hill under heavy load) This is when the sulphur smell (rotten egg) is produced.

Under relatively lean conditions, the sulphur found in gasoline is converted to sulphur trioxide, then during the rich running condition the sulfur trioxide is converted into hydrogen sulphide (rotten egg smell) within the catalytic converter."

So, you can try different brands of gas, or check and see if your Forward O2 sensor is lazy. If you are not getting a MIL (CEL) light, it's probably only lazy (e.g not switching fast enough.) Maybe you can find a shop with a O2 sensor tester. Before OBDII, that was the easiest way to see what they were doing. There is one for sale on the used and for sale section here. I'm guessing gas and maybe the lazy front O2 sensor.


Happy, and less smelly, Exploring

 

[410Fortune]

his 99 is OBD-II
Honestly if you dont have a MIL and the truck runs fine, I would ignore it for now, especially if it is intermittant as you say.

and follow the advise regarding the gas type.
See if you can find out if your engine is running lean (intake leaks, vacuum leaks, weakish fuel pump, etc)

A good scanner or OBD-II software interfacecan give you real time fuel/air curves and show you what your 02 sensors are reading at.
A fuel pressure test is also a good idea

 

[martin123]

Did a search and this is the closest posting to my problem. I have replaced my O2 sensors (last summer). Yesterday when I start the ex up it runs very rough and white exhaust, but once warms up it runs perfect and no white exhaust. Check codes PO422. Main Catalyst. Should I just assume the code is correct and change the cat. Could it be anything else? And is it an easy job of the driveway? Thanks

 

[Sams01XplrSprt]

i remember when my 01 sport had a bad sulfur smell it smelled like a sewer and for some reason now it doesnt smell like it anymore i dunno how it caused that smell before.

 

[bluestream1]

I would wait until you need the smog test and see if it passes before spending money on it. What does the air care test have to do with insurance? I don't see a connection...

 

[martin123]

Problem with waiting is the fuel mileage has dropped. I am getting very very bad mileage. Would rather spend the money fixing the problem, before I spend more money in gas than the actual price to fix it. Just need to know if I should trust the PO422 code and change the "Main Catalyst" or check other parts first? Also is it a job I would want to do in the driveway or take it to a shop? Changed all the O2 sensors last summer so they should not be stuck. But separating the rest of the exhaust system from the cat maybe hard? Thanks for any suggestions. (sorry about the long message)

 

[LBarr2002]

Well, yes I could understand a bad cat...if it had more miles, but 60,000 miles? And don't forget, the o2 was replaced 1 1/2 years ago.Could it be because it is used mostly in the city?Doesn't get too much highway miles.

My wife's 2003 4runner v8 has had that smell at times since basically new. I never follow her anywhere, I get to lead. My buddies '03 matrix did the same thing and there was a recall on it.