99 ranger 3.0 runs good for about a week then all of a sudden it will shut off. Acts like it runs out of fuel , let it sit for a few minutes and it will start up and run for a few minutes, and if I let it sit and not do nothing to it for several hours it will runs for about a week, replaced egr valve and sensor and the throttle positioning sensor, cleaned mas sensor , took it to advanced auto hooked computer on it and it had a 1451 code, any help would be appreciated

 

Here are some details on your code:

Technical Description

EVAP Control System Canister Vent Solenoid Circuit Malfunction

What does that mean?

The EVAP system monitors the canister vent (CV) solenoid circuit for an electrical failure. The test fails when the signal moves outside the minimum or maximum allowable calibrated parameters for a specified canister vent duty cycle by PCM command.

Symptoms

You will likely not notice any drivability problems.

Causes

A code P1451 may mean that one or more of the following has happened:

VPWR circuit open
Damaged canister vent solenoid
Canister vent solenoid circuit open or shorted to ground, power, etc.
Damaged Powertrain Control Module (PCM)
Possible Solutions

Verify canister vent solenoid - To verify normal functioning, monitor the EVAP canister vent solenoid signal PID EVAPCV and the signal voltage (PCM control side). With the valve open, EVAPCV indicates 0% duty cycle and a voltage approximately equal to battery voltage. When the valve is commanded fully closed, EVAPCV indicates 100% duty cycle, and a minimum voltage drop of 4 volts is normal. Output test mode may be used to switch output on/off to verify function.
Replace canister vent solenoid

That code does not seem to have any adverse affects on drivability. I am not expert though so lets see what everyone says.