P2015 Diagnostic Code in Dodge Avenger: Causes, Fixes, and DIY Solutions

I'm experiencing a persistent P2015 error code on my Dodge Avenger. The code appears only when I start the car after letting it sit for several minutes, hours, or even days. During these periods, the vehicle runs fine initially but will not maintain RPMs above 180 or so—this happens every time I restart the engine. The issue is that the P2015 code does not clear on its own and reappears consistently after restarts. I'm wondering whether this requires a simple part replacement, or if it's more complex and needs a professional $1100 diagnostic service. I have basic mechanical skills but am not a mechanic. I've tried cleaning terminals and checking connections, but the problem persists. Are there common causes that can be addressed at home? Any advice from owners or technicians familiar with this specific P2015 issue in Dodge Avenger models would be greatly appreciated.