Sulphur Smell 2017 GMC Sierra 6.2l

[Willy77]

Two weeks ago I noticed a sulphur smell coming into the cab at slow speeds when drawing fresh air through the vents. No odor when A/C on max.  I have had the truck into the dealership and they can't find the source. Anyone have any thoughts?

[JimCost2014]

18 minutes ago, Willy77 said:

Two weeks ago I noticed a sulphur smell coming into the cab at slow speeds when drawing fresh air through the vents. No odor when A/C on max.  I have had the truck into the dealership and they can't find the source. Anyone have any thoughts?

Welcome to the site.

 

Not sure how long the exhaust should last on the new trucks, but in the past that smell meant your catalytic converter was bad, or on the way to failure.

[Willy77]

On 9/30/2021 at 8:47 PM, JimCost2014 said:

Welcome to the site.

 

Not sure how long the exhaust should last on the new trucks, but in the past that smell meant your catalytic converter was bad, or on the way to failure.

That is what I was thinking.  I'm not getting any warning codes. I thought I would if catalytic converter was not functioning properly.  

 

When the truck is warmed up and idling I don't get the smell. Only when slowing down or coming to a stop when in motion. 

[pokismoki]

sounds like cheapo gas , try using Chevron w/techron.. you might have a lean AFR. ,