sulphur smell from exhaust...

[83cutlasssedan]

Noticing a strong sulphur smell from the exhaust after a going for a drive in my Cutlass. I just put in a new intake and a 4bbl carb. Don't really notice the smell at idle only after a drive. I've heard a few different things about what this could be.
1. Bad catalytic converter. It's about 26 years old.
2. exhaust manifold leak.
3. New carb running to rich.

What do you guys think?

 

[ERIC87442]

if id have to take a guess id say bad cat

 

[84dragcutlass]

sulphur smell would defiatly be a bad convertor

 

[dan2286]

The smell is usually caused by the gas. You can try different gas and see if it gets better. Even newer cars have that smell and nothing really can be done about it. There should be no reason to replace the cat if the car is running good.

 

[joe_padavano]

sulphur smell would defiatly be a bad convertor

Nope, sorry. Read the emissions section of your Chassis Service Manual. The sulfur smell is from an overly rich mixture.

 

[83cutlasssedan]

well that would make sense since I just put a 500cfm carb right out of the box on my 231 v6. I should probably buy the calibration kit that comes with different rods and lean it out a little.

 

[megaladon6]

the sulfur smell is from a non functioning cat. excess fuel in the exhaust is a completely different smell.
however a a rich condition kills cats. first i'd tune the carb, start by checking the plugs to see the running condition. after you do the carb you might want to look at a cheap cat, for the simple fact that the old ones are highly restrictive and it's 26yrs old and at least partially plugged.

 

[83cutlassowner]

just gut the cat and put it back on. prolly wont help emissions but might help with sound/ power. lol . might want to get the carb dialed in to

 

[pontiacgp]

if that cat lasted 26 years I'd say it was a good cat..but time to change it

 

[pontiacgp]

well that would make sense since I just put a 500cfm carb right out of the box on my 231 v6. I should probably buy the calibration kit that comes with different rods and lean it out a little.

you may not need to lean it out...your two primaries are smaller on the 4 barrel than the 2 barrel you just removed so don't go guessing what rods/jets you should be running...and if your going to doing exhaust work then do that first before you check to see if you have to do anything with the carb