CEL and bad fumes

I have a 96 rodeo LS with 165K. The CEL has been coming on since about 110K and now it's on permanently. I've had it reset but it just comes back on. It had horrible fumes and smelled real bad so I had the oxygen sensor replaced and it helped for about 3000 miles then the light came back on and the fumes are back. I don't just want to throw radom part at it can somone give me a good starting point. The original coses said it was a Cat Conv. but when you ping it with a hammer it sounds fine so I don't think that is a problem?? The fumes are gasious not the rotten egg smell of a bad Cat.

If you live near an autozone they will read the codes for free.

my best guess is it is the cat conv.

jegs.com has some nice affordable cats, but you will have to find a place willing to swap it in for you.

-Ryan

If your exhaust smells like gasoline and performance & fuel economy are bad, something is causing your engine to run too rich. If you put new cat(s) on it, you will just burn them up. Like Ryan says, you have to know what the specific OBDII codes are. You may have an O2 sensor issue, a MAF sensor issue, a misfire, plugged intake tube/air filter, any number of things!! Get the codes read & post them here. G/luck
Joel