Expert: Josh Fields - 2/11/2006

Question
Hi Josh,

I am currently considering buying a 4 dr 94 325i in the Dominican Republic. The one I saw seemed really well cared for, it did have the check engine light on, and the owner stated that it was because of the O2 sensor, and the irregular fuel octanage that is sold here.

Would fuel additives help compensate for the lack of quality control in fuel Octanage in order to prolong the life of the O2 sensor?

Thanks,

J

Answer
Jose,
 Yes, fuel quality can have an affect on O2 sensor life.  Usually they get gunked up and stop working shortly after.  The only additive I know of is Octane Booster, but I'm not sure that will help the "quality" of fuel.  

 O2 sensor's usually have a life span of 50k miles, but may differ based on several factors.

 Sounds like a good purchase, but I would have a dealership/mechanic put their scan tool on the car to see if the Check Engine light is REALLY for an 02 sensor, and not something worse.

 Good luck
 Josh