STRONG catylist smell

[dondiesel444]

going up hills or under a moderate load, I get a real strong catylist smell, like the exhaust is getting too hot, you know the "rotton-egg" smell. I don't have a CEL or misf-fire or anyghint, is it possible I have a cat clogging up?? any ideas what to check??
thanks

 

[BAYDOG]

I'd have to say she's running a bit rich, maybe a timing issue, but not to much you can do there. Also maybe a a TPS sensor??

 

[dondiesel444]

but isn't it wierd that I don't have a CEL if I had a sensor bad, like the TPS??

 

[XonDubs]

ide reccomend checking your CAT and o2 sensors also before any other things....to check the CAT you can usualy bang on it with a rubber mallet and if it sounds loose in it then theres your problem....and if you have a bad cat ide change the o2 sensor also because when the cat clogs up so does the o2

 

[dondiesel444]

my X has 4 cats on it I think....

 

[XonDubs]

it should only have one cat on it unless it has true dual exhaust...ive never heard of 4 cats before....

 

[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.) . I'm guessing gas and maybe the lazy front O2 sensor. Have the sensor looked at with a scanner and watch the switching rate.


Happy, and less smelly, Exploring

Chris

 

[dondiesel444]

thanks, it may be my O2 sensor, I think the catylist is still intact inside the converters, I banged on all of them with a rubber hammer and I didn't hear anything rattling around inside. I guess I'll look into the O2 sensors. If one or more is getting "lazy", eventually it will get slow enough to throw a code, right??