Got a 07 1500 4x4 quad with 4.7 in it. Out of the blue light comes on have it scanned and a incorrect purge flow pops up. I've made sure the gas cap is on, but wondering if anyone has some experience with this as to the most common issue.

 

Disconnect the negative battery cable for 5 minutes to reset the code. If it goes away -great if it comes back might have to get it checked out.
Here in Boston area when ever I pull in for gas, attendant wants to open gas cap before I can put it in park and shut off engine. One day I got pissed at the guy, but he did not know better, did not speak English. Just make sure cap is on and not to let the idiots open before you can shut the engine off or it will throw a code.

 

There's a solenoid that opens when the truck is started, on mine its located under the battery area, also, under the truck on the drivers side, the lines go to the charcoal canister, and the hoses are rubber, its possible that they are getting old and rotting through, causing a vacuum leak. That's the basic system, check these out if the code comes back after you reset it

 

Is just the solenoid valve under the battery or is that where the canister is also

 

There should be only 1 solenoid, but it may be in a different location, best way is to find the canister, and work back to the solenoid.