not sure exactly what's wrong wit my friends car im gonna go take a look at it after work. she says it stumbles will it warms up and does not idle correctly. could it just need a tune up? plugs? filters? ect. non turbo model. thanks for any help and have a wonderful holiday weekend!

could it just need a tune up? plugs? filters? ect

 

Yes.............

Depending on the miles, a MAF/IAC cleaning might/should be in order. Saab 4 cylinder engines are really nothing special, being a British Leyland/Triumph engine in sheep's clothing, so to speak, the electronics are Bosch, again holding little surprises as they are nearly identical to stuff found on a Subaru.

she says se thinks the o2 sensor is bad but I don't know how much she knows about cars to make that clam haha

she says se thinks the o2 sensor is bad

 

If bad, like the mighty Subaru, the "check engine" light will be on (of course the two are not exclusive together), there is also a knock sensor, looks like a Subaru one, same result if bad (retards timing 10 degrees, puts check engine light on). The electronic engine management is almost identical between Subaru, and Saab. (one is "the original" the other is Memorex, there is very little difference, other than the Saab parts are cheaper!)