check engine light came on code reader said it was a fuel rail pressure sensor. how do i change it? could it be something else? code was p0193. please help just bought the car 2 weeks ago.

drifter, are you experiencing any symptoms along with the CEL (check engine light)?

If the Fuel Rail Pressure sensor is malfunctioning you will have both a loss of torque (which you might not notice since the car is only 2 weeks with you) and sudden drops in RPMS. If you aren't sure about the drops, warm your car up then take it up a hill - going slow and then hitting the gas and speeding up a few times. It'll feel like the engine is about to stall, or at least that it's having trouble getting fuel to the engine.

If this is the case, I would recommend having a dealer or reputable repair shop replace it (about $320). It is an easy to moderate job, but one best done by a dealer/mechanic. The fuel system is under pressure and procedures and caution must be taken when de-pressurizing the system and replacing the sensor.

If you aren't having any other symptoms besides the CEL, wait it out a bit.

no i dont think i am having any of those symtoms, after i cleared the code it hasnt came back on yet. so i am waiting to see if it comes back on before i take it to the dealer. thanks for the answers

If the CEL does come back on in the next couple of days, get the code checked again. If it says it's the Fuel Pressure Sensor, then most likely it is and will need to be replaced. You can get away with driving the car for as long as you want, assuming you have little or no symptoms (Volvo states the car can suddenly stall, but this is unlikely), but be cautious went the car is under load (up hills, trying to pass somebody, etc.).