Ive had the GM S/C kit on my car since last summer. About 27,000km on the kit now. Exhaust is all stock GT exhaust(with 156,000km on it). I had a clogged cat a couple months ago and replaced the OEM downpipe/cat with one off a 02 sunfire GT w/40,000km that was written off ($40 bucks why not). The car runs perfect and sounds perfect as it did the with old OEM downpipe/cat on it.

The car drives around town fine and fine when lightly laying into boost around town A/F stays in lean to normal.

Here is the kicker though. When really really really laying into it WOT for a long stretch empty road I see my A/F guage read real rich that is when the egg smell starts when it's really rich. It doesnt do this when going into boost around town. Just when really laying into it and pushing it to the floor as far as she will go.

There is no performance problems with going WOT that hard as far as I can tell. The car just pulls and pulls and the S/C just starts to scream in the upper RPM (yeah baby).

I have never replaced the either of the 02 sensors on the car. It has the fairly new downpipe/cat on it that was replaced (why not keep it OEM it's nice and quiet).

Also by the way.....the car did this before I put on the other downpipe/cat before you blame it on that.

Any ideas? @!#$ty GM Tune?

rotten eggs is from being too rich and all that going into your cat. fix your rich problem. Maybe o2 sensors



My car may run 18s, but I can do your taxes in 10 seconds flat.
JBO lube - they would never have enough in stock and we'd never see RodimusPrime again

Do you think that you have any Carbon buildup, from when your old cat was clogged? May need to run a Seafoam or carbon cleaner to clean your system out. Just a thought.



SOLD!!!!!!!!!!!!

The car runs perfect. Only thing I know is it did this before and after switching out the cat with the newer one. I dont know if the smell is so much outside with running hard WOT but I can sure smell it inside the car.

I have never run seafoam or carbon cleaner on my car. With every oil change I put in a bottle of STP fuel injector cleaner that is about all I do (along with any other regular maintance items)

Maybe I should switch out the 02 sensors. But those can be pricey?

Its the cat, get rid of it, its overrated anyway










~2014 New Z under the knife, same heart different body~
______________________
WHITECAVY no more
2012 numbers - 4SPD AUTOMATIC!!
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WHITECAVY wrote:Its the cat, get rid of it, its overrated anyway

not allowed in a lot of states, gotta love montana



fully built 2200-TO4E T3/T4-HP tuners-373hp @18psi

if its the cat, just get a high flow cat. who cares. or get rid of it, i know alot of people that do in PA, and its illegal to do so. Not a big deal, a cop said my exhaust was illegal and to loud, but he never got on his knees to go check. Thats the thing.

Does anyone remember what I say about cats?

A rotten egg smell is caused by the sulfer content in the gas. It just happens from time to time. Does not neccasarily mean the gas was bad per say just a litle high in sulfer. I really would not sweat it. My car smelled like that every once in a while even when it was stock.



FORGET GIRLS GONE WILD WE HAVE GOVERNMENT SPENDING GONE WILD!

a stuck vent solenoid for your EVAP system can also cause a rotten egg smell especially just after hard acceleration



ASE Master Certified Automotive Technician

Wade Jarvis wrote:Does anyone remember what I say about cats?

A rotten egg smell is caused by the sulfer content in the gas. It just happens from time to time. Does not neccasarily mean the gas was bad per say just a litle high in sulfer. I really would not sweat it. My car smelled like that every once in a while even when it was stock.

That is what I figured but I didnt know.

CaliforniaDomestics wrote:a stuck vent solenoid for your EVAP system can also cause a rotten egg smell especially just after hard acceleration

Do you have a diagram were the vent solenoid is? It doesnt happen all the time only under hard acceleration. Should I look at replacing it? It has done this the odd time when Stock as well. But being S/C just worried about it a little.

Regards,

A few months ago I had only a CAI and nothing else added to my car. I also noticed that weird egg smell when going open throttle. I soon upgraded my ehaust ( spark plugs, new o2 sensor, high flow cat) and the smell hasn't come back yet. Might be one of those thing's?

gut the cat and weld the shell like the rest of us, you don't need a cat.