We need some help with our 2006 Volvo XC90. We received the reduced engine performance light and it went into limp mode. The mechanic changed the electrical plug on the throttle body, but the next day, we had the same issues. I then cleaned the throttle body and changed the whole PCV system and the car worked great for 2 weeks. While driving in PA, I hit a pothole and the car immediately went into reduced engine performance again. I made it home to MD and the car worked on and off for about 2 weeks again. I disconnected the battery, waited two days, reconnected the battery and started the car and it was running fine. I closed the hood, and it went into reduced engine performance again and was sputtering! Waited a few minutes and it was running ok again. I am wondering if it is something electrical that could be loose. I am looking for suggestions. My mechanic told me that all systems checked out fine. Reduced engine performance is sporadic. Please help!