2006 Town & Country Running at high RPM
 

Hello everyone,

My 2006 Chrysler Town & Country has recently started to idle and run at 1500-2000rpm. When turning the van on, it jumps up to 1500-2000rpm, and once I shift into gear it drops down to 1100rpm; but once I get on the road it goes back up 1500rpm and doesn't drop from there. When I approach a stop sign, I have to keep my foot on the brake pedal, if not, the van will accelerate on its own. While idling, the van sounds like its taking in a lot of air, and some really faint black smoke comes out of the exhaust. While running, the van feels like its yanking.
I have checked the air intake and filter and everything is fine. I did put in a scan tool, and two codes pop up, an oxygen sensor code and a catalytic converter code. However, I erased them before going for another test drive as they usually pop back up on my scan tool, but this time "P0171: System Too Lean Bank 1" code popped up. And it has been the only code that popped up since, no more o2 sensor or cat codes.
What do you think it could be?

Engine Type: V6 3.8
Mileage: 103,450