Exhaust odor

[TimTim]

OK you might think this is a odd question but, I bought a used 2500HD with 9000 miles on it. I have put about 500mi. on it and from day one the exhaust fumes after it warms up smell like a cross between sulfur and rotten eggs.

 

Is this a common odor with the 8.1?

[Chris97K1500]

At least with my old Toyota truck and current 4Runner, when the exhaust smells like rotten eggs/sulfur, time for a new catalytic converter. 9000 miles seems kinda odd to be needing a new catalytic converter. Could be different on the GMs, but after replacing the cats on my Yota's the smell went away. Chris

[michigan2500hd]

Had same problem with my 6.0 2500hd. Bought new last year and from about 200 miles on it started stinking real bad. More so after stop and go driving. It has just lately started to lose a little of the stench. Dealer has looked at my truck many times and could not find any problems. They did replace both converters but it didnt help. Everyone has told me it will go away after I put 10-15,000 miles on it.

Sorry I dont have better news. I have tried almost everything, changing brands of fuel,octanes,converters etc. I just put a flowmaster 50 on it , will see if this makes a dif.

[c502cid]

The rotten egg smell (sulphur) is not from a bad cat, it is a reaction going on in the cat from too much fuel. 99 times out of 100 it is not the cat at fault but either a bad map sensor or a bad O2 sensor. Both cause too much fuel to be in the mixture and the result from that is the smell. I'm surprised you aren't getting a check engine light but the first thing I'd do is get the codes read.

[THE BIGPUNN]

i was at a wedding reception earlier this year and oddly enough at my table was a gentleman who works with GM and has a lot to do with engines. a lady asked him about the same smell from her car, (dont remember what her car was), but he recommended a change in spark plugs. i dont remeber thought if he recommended warmer or colder however.