I am the new owner of a 98 s70 GLT 125k miles, and I've never owned a volvo before. Starting running rough both idling and while driving. Check engine light is on, but the code reader I am using reads "no codes." Any ideas? Bad code reader maybe? Any help is appreciated.

Thanks, Mike

 

What kind of "code reader" do you have? Does it read OBD2 codes? Are you a DIYer? Have you tried a tune-up or stage0? etc.