well, not literally! anyhoo... i was in front of my friend and he said that everytime i acclerate hard, it smells like eggs. I know this means a bad cat, but what could be causing it? I think i've heard something about high speeds will do it but exhaust flows at the same rate at the same rpm at any speed (ie: 20mph @ 5000 rpm exhaust flow = 120mph @ 5000rpm exhaust flow, iirc). What could be going wrong?

 

if your engine is running rich, the raw fuel that finds itself in the exhaust stream can damage your cat. either that, natural age is getting to it. other than that, i don't know, but those are my guesses.

 

well, it's got 140k miles on it and I have no clue on how rich or lean it's running. there's not much soot in the muffler when i took it off...

 

You are running rich.
Change Cat and o2 ASAP

 

and how might i change the fact that i'm ruinning rich?

edit: it's stock.

 

Hm, my car doesn't smell like that.

Time for more eggs. Do you sell eggs?

 

check your sparkplugs. if you're running rich, they plugs will be pretty fouled up with carbon buildup, or can even be a little moist.

 

I.E. Black
Fixing the condition is easier said than done.
I always recommend starting with the 02 because it is the single most neglected part on a vehicle. While at the same time it is VITAL to your car performing optimally as well as Mileage and emissions.
You may also have faulty injectors that are just poyuring the gas into the cylinders instead of spraying it.

 

they are normally worn... no wetness (even after a few WOT pulls), no carbon buildup. My o2 was changed 40k miles ago, and my MAF is not coated with the infamous k&n oil. Sometimes, it idles like it's cold, even though it's a normal operating temp. IAC valve looks brand freaking new. I havent thouched the EGR (everytime i've worked on my car, it was too hot to take off) so I'll do that today.

I *might* need to change/recharge my filter.... O_o

Does this help?

 

Raw egg smell has nothing to do with the shape of the Cat. For a long time GM had a terrible problem with some of their vehicles coming from the factory that way.