2005 XC90 V8 P2401 CEL

[wgc2005]

I recently changed out the fuel rail pressure sensor as my CEL had come on and indicated that the fuel rail had low pressure. After reading on this forum I changed out the fuel filter which did not correct the issue. I then changed out the fuel pressure sensor which eliminated the CEL. During this replacement, I had difficulty getting the bolt which holds the pressure sensor to the plastic housing out. This was due to the nut which is embedded in the plastic turning while trying to back the bolt out. I tried everything to hold the nut in place, but had no luck. I then removed the fuel rail and injectors to get the assembly out and removed the bolt via a cutting wheel. I was very careful in putting everything back in place and ensuring that the o-rings were in place on all components during the re-install. I now have the CEL on indicating "P2401" which indicates evaporative system issue. Would this have anything to do with improper re-install? This code was not being thrown before the maintenance work, so it leads me to believe I have caused it, but I do not know much about how the evaporative system works. Any help would be appreciated. Thank you.