I have a 98 s70 non-turbo. The check engine light has been on since I bought the car. I recently ran it through a scanner at a localmechanic and it said I had a cylider misfire. I changed all the spark plugs, wires, distributor cap, etc.

What the car started doing like 2 months ago is shutting off sometimes. It would drive, and then all of a sudden the RPMs would dip all the way down to 0 (hence, shutting off). I was already getting bad gas-mileage (17mpg in city), but NOW, it's really bad -- only 13mpg!

When I ran the scanner, it showed that there was an issue with an O2 sensor. Does anyone know if this is the cause of the problem of the car shutting off and the poor gas mileage? Or could it also be the Mass Air Flow sensor?

Thx for your help in advance.

 

Getting poor gas mileage could very well be due to the 02 sensor being broken/busted/mess up or whatever it may be. I would get that replaced/fixed or at least checked up on. I didnt see that you mentioned the MAS, that could be it too, I would get 'em fixed.

 

What type of an O2 sensor +MAFwould you guys recommend? Where from? How much would it cost?