Fuel pressure regulator or not?

Hello,
I'm new to this site so bear with me. I have a 99 intrigue and have had a problem with it for about six months. Now the first thing is when its cold it idles up and down alot, and when I try to drive it in the mornings it wants to bog down on me and it has no power but after it warms up it runs somewhat better. Unfortunately it uses a lot more gas and it smells like rotton eggs. Also, when I drive on the interstate and start to go up a slight hill my check engine light will come on for a bit. I've had plugs,filters, and other things checked but they can't find the problem , the code reads multiple miss fires. what is the problem?
thanks for any help you can give
slewwfoot

If the codes are reading misfires then the likely place to look is at the ignition system. Plugs, coils, etc. Typically the misfire code will specifiy which cylinder was misfiring.

thanks,
I had the plugs , wires ,plugs and all replaced so i just dont know what to do.

I dunno what your prob is, but i suggest you check and change everything. Check your radiator too clean everthing out. So then there will not be many possibilities. About the rotten egg smell, does it always smell like that? or only when its cold? Thats weird! GOOD LUCK

IT smell bad when its hot and cold but not all the time.

Is it the motor that smells or the car or inside the car? Or when you turn on your ac?

I was told that the smell was from my catalytic convertor , they said that my car was running to rich on gas and the smell was my catalytic convertor burning off the extra gas

Just cut out the damn cat. It's only there to lessen pollution. It's totaly legal for you to take it off, and besides it will make your car sound more aggresive. (Plus no more rotten eggs)

Once again I would suggest that you get into the codes to see if it is one cylinder misfiring or all of them.

You can has an oxygen sensor built into it to tell the computer if it is running rich or lean. Some scan tools allow you to read the data out of (among other things) the oxygen sensor. If the car just seems to be running rich and the computer has backed down the adjustments all the way (you should also be able to read this with the tool) then perhaps you have a leaking fuel injector.

If you intend to try and fix this yourself, I would suggest that you consider investing in a tool like: http://www.obd-2.com/ (I have no relationship with them other than being a happy customer).

If SC has an emissions testing program then you certainly will have a problem if you cut off your CAT as you will fail the certification testing. It may make the car sound more aggressive but it will also change the shape of your torque and horsepower curves. The 3.5 (IMHO) doesn't have enough low end grunt as it is and cutting out the CAT will only make that worse.

Thanks for the info I will have it checked to see if it is misfiring on one or all the cylinders.