Bad fuel rail pressure sensor

The ECU in my wagon is throwing the P0193 - Fuel Rail Pressure Sensor High fault code. I have an OBDII bluetooth reader and have reset the ECU fault codes and have been monitoring the reading from the FRP sensor while driving. It gives a nice flat reading of 40 psi most of the time but once in a while (especially when the car first starts) pegs out to the maximum 5V reading of 72 psi. When this happens it is almost always while I am coasting or idle, then usually goes back to a normal reading when I accelerate again. I do not notice any difference in the engine when the sensor pegs to 72 psi. It can go quite a while (a week or so) without an errant FRP sensor reading, but then it will peg out again briefly and throw a P0193 code again. This seems to me like a bad sensor, am I right? Is there any other explanation (intermittently failing fuel pump, for instance) that might be the cause of this? I am getting ready to order a replacement sensor and wanted to run this by someone knowledgeable first. Thank you!