1998 Volvo V70 GLT, AWD (auto)

So did a test, and my info screen is correct and I'm only getting 10mpg city driving (driving like a grandma). Just discovered that the check engine light must have been disconnected at some time. But connected my OBDII and it came up with these codes:

P0130 - Powertrain: O2 sensor circuit (bank 1 sensor 2)

P0305 - Powertrain: Cylinder 5 misfire detected

P0300 - Powertrain: Random/Multiple cylinder misfire detected

P0102 - Powertrain: Mass or Volume Air flow circuit low input

P0302 - Powertrain: Cylinder 2 misfire detected

P0137 - Powertrain: O2 Sensor circuit low voltage (bank 1 sensor 2)

Assuming I will need to replace the MAF (currently has a refurbished one the owner before me must have put on) before anything. Hoping that will fix the other problems. Any thoughts on that, or should I try something else first?

Also would any of this cause the terrible gas milage I'm getting?

Let me know if you have any thoughts on the mpg or how I should go about looking into all of these codes it brought up.

Thanks

 

Yikes! Reset the code, drive a couple of days and check again. The bulb may have simply blown out from being on all the time. A lot of mechanics tell people to ignore that rear o2 sensor code.

Also figure out how hot the car is getting while warm.