After a five mile trip, my 94 volvo 850 turbo wagon smells like rotten eggs. The smell goes away after a while. Is something burning? Should I be worried?


Sounds to me like your catylitic converter is plugged and heating up causing the rotten egg smell to enter the inside of the car. Usually this happens with a brand new cat. converter but it has happened with old ones also once then get plugged and heat up. I would try replacing it and go from there. There really isnt much more that can smell like rotten eggs and then go away like that.


It sounds like two problems to me. A failing converter and an exhaust problem allowing it into the cabin.



The “rotten egg” smell is a by-product of unburned unleaded fuel combining with the catalyst in the catalytic converter. You have two issues:

  1. A failed converter-- replace it with the factory unit only-- yes- they cost more but they are designed for that emissions system of that specific powertrain.
  2. You have a fuel management issue. I would suspect that you are also experiencing poor fuel economy or other symptoms (such as rough running) due to fuel management. There could be several causes to this problem-- including- 02 Sensor, MAP Sensor, MAF Sensor, etc. Take it to the dealer and insist they check for both. If you’re in CA, you may be in luck since emissions systems are warrantied for 100k miles in some circumstances.

Regardless, a failed “cat” can cause the exhaust system to overheat-- a safety issue- and it can cause premature failure of other components in the exhaust system.




The “rotten egg” smell is most likely caused by sulphur in the fuel you are using. Attached is a Volvo TSB regarding this issue. Replacing the three way converter will not help this problem.