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Rotten Egg/sulfur Smell?

08AllTerrain

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08AllTerrain Enthusiast

08AllTerrain

Posted
Posted

Hey guys, so Ive noticed this smell every so often in my truck. I seem to only notice when I have my tune in also, did a swap for awhile to check and no smell with the stock ecm module. Any ideas what it might be? 08 Sierra 5.3, GM Exhaust/CAI with 93 Tune burning 93 octane in it..it smells like a catalytic converter smell but again, only seem to smell it with tuned module in.

bronyaur Enthusiast

bronyaur

Posted
Posted

I've also smelled rotten eggs when my Optima battery decided to die. The smell showed up a couple of starts before it actually died.

greatmizzou Enthusiast

greatmizzou

Posted
Posted

I had a very bad smell like that when I had battery issues, I had a subwoofer installed into a mustang and it turned out it just bled the battery even when engine was off, very very bad smell

jro909 Senior Enthusiast

jro909

Posted
Posted

the smell also comes if you pound on the throttle....its from the cats

  • 3 months later...
EvolutionX Enthusiast

EvolutionX

Posted
Posted

I was just going to start a new thread about this same issue when I came across this thread. I started having a natural gas/propane type smell in the cabin when driving my Denali. It worsens the longer I drive to the point where its unbearable and gives me a headache. From my knowledge I immediately thought, Cats. But, to be sure I took it to my local GMC dealer since if it was indeed the Cats, that should be replaced being under warranty (80,000 or 8 years). Of course the dealer calls and tells me they cant find any problems, and smell nothing. Idiots, since its very noticeable. I told them to drive it on the freeway today and it will smell for sure. So the above posters say this is a cat problem??? I have a Magnaflow after cats setup with turn down and K&N cai.

RJG183SA Enthusiast

RJG183SA

Posted
Posted
Hey guys, so Ive noticed this smell every so often in my truck. I seem to only notice when I have my tune in also, did a swap for awhile to check and no smell with the stock ecm module. Any ideas what it might be? 08 Sierra 5.3, GM Exhaust/CAI with 93 Tune burning 93 octane in it..it smells like a catalytic converter smell but again, only seem to smell it with tuned module in.

 

IIRC, I read a GM bulletin that stated some low tier fuels contain higher amounts of sulfur and can create the excessive odor. You may want to try a top tier brand of fuel.

EvolutionX Enthusiast

EvolutionX

Posted
Posted
Hey guys, so Ive noticed this smell every so often in my truck. I seem to only notice when I have my tune in also, did a swap for awhile to check and no smell with the stock ecm module. Any ideas what it might be? 08 Sierra 5.3, GM Exhaust/CAI with 93 Tune burning 93 octane in it..it smells like a catalytic converter smell but again, only seem to smell it with tuned module in.

 

IIRC, I read a GM bulletin that stated some low tier fuels contain higher amounts of sulfur and can create the excessive odor. You may want to try a top tier brand of fuel.

 

I run Shell 87 always and this propane/natural gas smell just gets worse.

tanked_darren Senior Enthusiast

tanked_darren

Posted
Posted
Hey guys, so Ive noticed this smell every so often in my truck. I seem to only notice when I have my tune in also, did a swap for awhile to check and no smell with the stock ecm module. Any ideas what it might be? 08 Sierra 5.3, GM Exhaust/CAI with 93 Tune burning 93 octane in it..it smells like a catalytic converter smell but again, only seem to smell it with tuned module in.

 

IIRC, I read a GM bulletin that stated some low tier fuels contain higher amounts of sulfur and can create the excessive odor. You may want to try a top tier brand of fuel.

 

 

Oh don't bring up top tier around here, I did that once and it started a huge arguement that never had an end.

 

I only use top tier fuel and I never use those shitty fuel injector cleaners, those are a waste of money.

jrrod2004 Senior Enthusiast

jrrod2004

Posted
Posted
Hey guys, so Ive noticed this smell every so often in my truck. I seem to only notice when I have my tune in also, did a swap for awhile to check and no smell with the stock ecm module. Any ideas what it might be? 08 Sierra 5.3, GM Exhaust/CAI with 93 Tune burning 93 octane in it..it smells like a catalytic converter smell but again, only seem to smell it with tuned module in.

 

IIRC, I read a GM bulletin that stated some low tier fuels contain higher amounts of sulfur and can create the excessive odor. You may want to try a top tier brand of fuel.

 

 

Oh don't bring up top tier around here, I did that once and it started a huge arguement that never had an end.

 

I only use top tier fuel and I never use those shitty fuel injector cleaners, those are a waste of money.

 

 

Yes, no to the top tier issue. do what I do: pull the battery (allowing the computer to reset). Fill up on 93 octane and then drive it with a good amount of throttle. mine wasnt the cats...I guess some type of build up. Went away and has never returned (dealership was of no help at the time). I do this once a year...usually in the spring but I dont think it will work for you....

EvolutionX Enthusiast

EvolutionX

Posted
Posted

An update on my gas/propane smell on the Denali: Got it back from the GM dealer and of course they said they found nothing and couldn't even smell anything. I ended up making a tech come with me while I drove it and then miraculously he could smell it too. The conclusion they came to was a bad tank of gas, since it has happened on this one tank I've been running. I tested the theory after paying 100 for them doing nothing of course, and ran the truck down to empty as much as I could. Filled up with Shell 87 as usual, and since then the smell HAS dissipated. I get a small whiff of it at first drive but later I really don't notice it. Weird that bad fuel could cause a propane smell, as I always thought it would just cause knock.

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