hawkeyez

Hey I was just wondering if anybody was having a problem with their factory cat. I own a 05 Red SS/SC with 9,910 miles on it and I am having a problem with a rotten egg smell coming from the car when i get on it and sometimes when I dont. I took it to the dealership and they said that all is ok and that the sensors are fine as well as the cat flowing fine. They told me to try new gas which I did and that does not work. I only run high octane 93. I bought the this car this year from a chevy dealer with just over 6000. Dont know what to do.

BlackSS05

well it seems to be NY people. dealer told me its because there O2 in the gas in the winter or something that makes that smell. and also there was nothing wrong. i really want to call bs but i cant prove nething. second run shell vpower all the time. it seems to me that when i dont run that it smells but when i do i dont get a smell. And where in NY are you located??

Brian MP5T

If you drive it hard it will smell more...

knatsabooh

my old euro used to do that. It was a 91 tho and getting older so that likely explains that. It was gross tho, kinda smelt like propane / eggy farts. Hope I don't get that with my car when it comes... hehe .

hawkeyez

Thanks guys for your help. I really dont run the car hard just every once in a while I will get on it. I try to baby the car so when i need the power i have it.

alleycat58

This might sound crazy, but have you gotten the GM reflash for the rough idle TSB? I noticed you have a 2005 as well, I had the same problem with my car and the rotten egg smell, the guy at the dealership said they'd do the reflash for the rough idle and it should correct the smell. Funny thing is, it did nothing for the idle problem, but it did fix the smell - I haven't noticed it once since getting the reflash done. No idea why it fixes it, but it does.

hawkeyez

I live in upstate NY near Abany

hawkeyez

reflash huh never heard of that. what does it consist of. I will try anything.

hawkeyez

what year was your cobalt

alleycat58

Mine is an 05 as well, which is why I suggested you get the reflash (it's free). The Bulletin # is 05-08-49-002A. It fixes the cold start/rough idle issues as well as erratic fuel gauge readings and the side benefit is it takes away the exhaust smell. I would just give them the bulletin number and tell them your fuel gauge is acting up and/or you've got rough idle issues since the exhaust smell isn't listed on the bulletin.

Cams

I'd say that it might be your clutch. Clutches tend to smell like rotting dead fish eggs animals whatever. Not a pretty smell at all but generally clutch.