Volvo: 1998 s70 SE Emission System Service, high octane fuel, emission system

Question
Hi,

My Emission System Service light's on after the following sequences of events.

I was filling a marine gas can with high-octane fuel (which contained 2 cycle oil), and immediately topped up my S70s tank with the 94octane.  I accidentally let the marine mix hit the nozzle before topping up the car.
I'm not sure if enough 50/1 drops of 2 cycle oil could cause this, or is it simply the high octane that's not needed that's tripping this sensor).  There is no change in performance.  Should I wait to see if the light resets after I refill with 87octane?  Or can I reset by removing the fuse?

Thank you,

Pat


Answer
My guess is that the mix of 94 and 87 octane is what caused the sensor trip.  I doubt the oil makes a difference (if some did get in, it will just burn off).  I would wait for the next tank (or two) of 87 octane and see what the sensor does.  If it doesn't go off, before resetting it yourself, I would have the car checked, especially the injectors, to make sure nothing in fact did go wrong.  Good luck!