Tried 3 different fuels with different octane. Whatever it is, the smell went away for 30 days after the new cat was installed. Now has returned just as some postings said it would. GM says everything is in spec. Maybe get a pint of perfume. Will put solenoid on things to do. Thanks.

its supposed to click, once anyway. if it continues clicking i would unplug it to be sure thats the problem before just replacing anything. its probably by the fuel door on the inside of the fender with a two wire plug and a bigger line going to it

did you try 3 different octanes of fuel from the same stop or different locations? sounds like a fuel quality concern! Id try fueling up at other places around town if you are not already!

good luck- hope it works out!

Agree w Justin. Check your evaporative system. Clicking on a back is a sound of your evap canister makes when evaporative valve purging it. Could very well be that ur valve is going bad, it is usually located on the engine somewhere. It could also be pretty much any other component in its system such as lines and so on.

Aaron. Tried 5 different fuels now. All major brands. Still have foul odor.

How is your MPG?

Not the greatest Mike. 16 city. Very smooth idle. No black smoke out of exhaust. Just odor.

Ok, a 3.5L should not be getting 16MPG, and with a rotten egg smell out the exhaust, its running rich.

Have you ever followed another car on a flat stretch and then started going up hill and all of a sudden, you smell the same smell your smelling? That'* because the computer increased the amount of fuel going to the engine to compensate for the hill. Same thing seems to be happening here in your case, but its constant. This is why your MPG sucks.

Are you sure your fuel pressure regulator is working correctly?

mike made me think of something, not sure how you would check but, there are two programs for e85,&gas and maybe its stuck on e85, that would make it run rich with gas.

also if you dont ever drive long enough to get the cat hot to burn out the stuff thats not good for it either

I was a delivery agent for 25 years. I know about the smell when you punch it sometime but mine does it at idle. Smells up the garage. It was at the dealer and they said no codes. Would that not have shown a regulator problem? Thanks