Evap Codes

[mhorgan]

Ive got a P0440 and a P0452 in my 02 Z71. I bought it with 165k on it 2 yrs ago as a work truck and had to replace the fuel pump about a year and a half ago at 185K. Ive had the intermittent P0440 code since replacing the pump and it clears out, but now it's steady along with the P0452. I figured the purge solenoid might have been sticking open and causing the P0440, but it's also been hard starting prior to these codes coming up. Usually wont fire on the first crank (more like the 2nd or 3rd) but it will stumble if and when it does. I can hear the pump priming when I turn the key on and Ive already replaced the FP regulator. My guess is that I have a bad FTP sensor, but can that cause a P0440? Can I replace the FTP sensor without having to swap the whole fuel pump module? Other than the hard start, Im not having any other driveability issues. Anybody have a place I can start?

[8.1HD/ALLISON]

P0440 is evap system leak. If the gas cap wasn't loose, take to the dealer and have them diagnose it. They will pressurize the system with nitrogen and check for leaks.