Hello, I will try to help. Run a bottle of Techron through the fuel system to clean the injectors first. It may help if you have a dirty or hung up injector seat. Even though you do not see a check engine light, I believe you may still have a code stored. So I would scan the ECM and check. Sometimes the processor has to see a fault numerous times before it will set off the light. You can drop in an Oreilly or Advance Auto and scan the OBD II system. That being said, You may have a defective ETM (Electronic Throttle Module) or a dirty throttle body, in which not enough air cannot come around the throttle plate to make the engine idle well. Volvo has had alot of trouble with their ETM's so I would not be surprised if yours is acting up as well. If this problem started after a fill up of one tank, I wait and run another tank of fuel through it before suspecting any component failures. But if 2 tanks of fuel make no difference in the problem, then I would suspect an issue. Also, make sure the plugs and air filter are up to date as they are normal maintenance items that could possibly cause a rough running issue.Edward Clayton41031.8147868866