What is causing this, engine is 383.

Eric

 

Exhaust leak more than likely.

 

Sounds like clogged cats. That is the only think that I heard that can make that smell. Though the guy at GM said that a bad EGR could make that smell, but I have had a lot of cars with a bad EGR and never made that smell.

 

it goes into 2nd gear with a light load, it is a 383 too, I took the pipe off the egr and ran it and it still pinged.

 

If it is pinging, your motor could be running lean and causing the cats to run hot which is not good and I think might be able to cause that that smell. Anyone else?

 

stock 130,000 muffler and cat, come guys IDEAS????

 

Dont know if this helps or not, but used to be a service manager for a Mitsubishi dealer, had the same complaint, usually after a lot of accelerating. Customer would complain of rotton egg smell from exhaust. Tech bulletin stated smell was due to low nickle content in catalytic converter, but converter still functioned properly otherwise. If customer continually complained about smell we could replace it with a converter with higher nickle content.

 

Your EGR is leaking.

 

you seem to know that this is the problem.

Eric

 

Someone else recently had the same problem and posted the solution here. Do a search.

 

never found the thread, help...