Sulfur Smell When I Floor It

[acidbug]

Excerpt from yourmechanic.com

A sulfuric or rotten eggs smell indicates an excess of byproducts left over from failed combustion. Removing the smell requires part replacement.

The byproducts and deposits causing the smell are left over from the incomplete combustion of gasoline being burned and can be traced to multiple system failures. Should the smell only occur briefly after using the engine at high revs, there is no serious issue to be concerned about. A lingering sulfur smell, however, needs to be investigated. Listed below are 3 reasons your car smells like sulfur.

1. Broken Catalytic Converter​

2. Failing Fuel Pressure Sensor or Worn Out Fuel Filter​

3. Old Transmission Fluid​

 

[Steve88]

Hi Folks,

I have a 2021 CX-5 Signature. Currently has 19K miles. I notice that whenever I floor the car in regular or sport mode, a sulfur smells enters the cabin. I am wondering if this is normal with these turbo skyactiv engines, or if it could be a leak in the exhaust manifold, problem with the catalytic converter, faulty fuel filter or fuel pressure sensor, etc. It ONLY happens when I floor it. Otherwise I do not smell anything. Has anyone else experienced this? Thanks for any feedback!

Hi - I have a 2020 CX-5 GTR which obviously is a Turbo. I actually experienced this repeatedly exactly as you described. I was using Costco Gas - supposedly the best tier. I used 87 as well as 93. I think the 93 octane was a little improved but I could still get sulfur smell into the cabin when punching it. The smell would typically be noticeable after letting up on the throttle (maybe 2-4 seconds after the acceleration burst). Recirculate setting seemed to do the trick but in my mind it was just a bandaid for something which should not be happening. Also, under normal driving the recirculate setting has a noticeable but difficult to describe smell which I am not happy with.

Switching to Sunoco 93 was a small improvement.

I could not get a rational explanation from the service writer at my dealership.