I've got a 1989 IROC with a 305 tpi 5Speed dual cats(2 years old) car has 17,700 orig miles.When i get on it hard there is a bad smell like something rotten.Under normal driving cond. it's fine.Can any one tell me what's up.

 

The smell of rotten eggs is from the Cats and is normal.

 

Thanks for the reply.Just wondering because i never had it happen on my 95 z. When it had a cat.

 

I don't recall ever smelling rotten eggs while behind an f-body before. I've only smelled that crap while behind certain car makes.

 

I always though that when your cats start smelling like that, it means they are going bad.

 

Actually it means you are running rich. If you run rich that will kill the cats.

 

If it has a bitter sweet smell it is coolant. At the age of your car you might need a heater core. Under load the cooling system builds more pressure and it leaks alittle more. Keep a eye on your coolant level and if you have to add any then I would check that. Also if it breaks loose you will have the right front carpet soaked. You windshield will also get a grease film.
If it is the converters under load the car will bog once they get restricked. The car will start loosing power and the more gas you give it the slower it will go.
You did not say what how it smelled so I thought I would tell you about the heater core. It is something you should start watching now. Hopes this helps.

 

The smell is like rotton eggs.The cats was replaced with oem setup,which have 10,000 miles on them.The engine dosn't seem to be running rich unless at wot.As soon as I get out of it it goes back to normal.I'll try reajusting the tps.THANKS AGAIN