A few weeks ago I bought an 05 f150 with the 5.4 and 115k on it, since I bought it I've had slight issue when starting it. It has never stalled or not started at all but it takes longer than normal of holding the key before it starts, maybe 3 seconds or so. But like I said, it always starts, and has never died or stalled while driving

While leaving the parking lot at work today the check engine light came on, I drove to an autozone and had the code read, the only code he saw was a p0191 which is "fuel rail pressure sensor circuit a range performance"

now I know the code says the fuel rail pressure sensor. My question is should I start with the sensor, then the driver module then (hopefully not) the fuel pump? I know the driver module is known for rotting out and failing on these trucks, should I start there and then do the pressure sensor, then if neither of those fix it, the fuel pump? The sensor and the module are each a little over 100 bucks and obviously the fuel pump will be probably around 500 bucks so if based in the symptoms it's more likely one of the 3 than the others, I'd rather not fix all 3. Any insight?

 

I forgot to mention when it comes to starting it. If I recently drove it it has very little if not no problem starting up, it takes a couple extra seconds the longer it has sat.

if I drive it home, and try to start it ya know 10 minutes later, starts right up. If it sits for hours or even days it still starts every time but takes several extra seconds