Sulfur Odor From Exhaust - keywords calibration catalytic controls driveability ECM engine L61 PCM

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in the PI.

Some customers may comment on a sulfur or rotten egg odor coming from the exhaust. Vehicle conditions such as extended idling, hard braking, aggressive acceleration and long wide open throttle maneuvers, or driving in reverse may intensify the odor.

This sulfur odor is not an indication of an engine concern, nor will it result in reduced driveability or durability of the engine or any of the emission components. This odor is a result of sulfur reaction in the catalytic converter during vehicle operation. The odor is more common in newer vehicles. Sulfur is a natural component of crude oil from which gasoline is refined and the amount of sulfur can vary between different sources. As the vehicle ages, the severity of this odor should diminish.

Replacement of the oxygen sensors or the catalytic converter will not reduce this odor.

If there are no DTCs stored, no engine misfires, and normal scan tool data noted, recalibrate the ECM with the latest calibrations. An updated calibration was released to address this issue in March of 2004.

Please follow this diagnosis process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.