I have a 95 850 glt n/a engine number B5254S ... ok i have 2 easy questions one my check engine light came on and i got it checked through the diagnostic port and it said slow response from the o2 sensor they cleared it and it came back about a week later ... Does this mean the car needs a new one its about ready to go or could it be something else wrong. I checked the codes under the hood and it also came up oxygen sensors. The next one is stupid when i went to price a o2 sensor they asked if i had a pump or no i have no idea what pump they askin for does anyone know if that engine has one and whatr pump it is.?

thanks

They asked you if your car have an AIR PUMP (anti-polution related system)
The O2 sensors is different for those cars
Check out the link below and you'll know right away if your car have one.

http://volvospeed.com/Repair/airpump1.htm
--
Dennis

LC,

It's very simple. There are different o2 sensors for Turbo models and non-Turbo models. That's all you really need to specify. Which 850 do you have? If you went to the dealer for the part, make them go out and look at your motor if you're still not sure. If they refuse, dump the dealer and find your parts somewhere else.

O2 sensors go out and need to be replaced. If you got a specific O2 sensor failure code, either the front or the rear needs to be replaced.