my car is running temp all the way on hot and loosing power to 25-30mph for about 5min then pick back up. The manchine read a code p0446 can you tell me whats going on

P0446 Evaporative Emmission Control System Vent Control Circuit - A code P0446 could mean one or more of the following has happened: Faulty vent valve -- Open, short or excessive resistance on Vent valve control circuit -- Blockage of vent valve -- Bad PCM

check to see if your rad fan is working, could be a bad fan or relay or something, causing it to run hot, it will reduce power once it starts gettin to hot to "protect" itself from damage, the p0446 code is correct on the emission control system, and again it could be a bad vent solenoid or a blockage in a vent line from the gas tank, pretty sure the 2 arnt connected unless the pcm is faulty and causing bad communication between sensors and stuff

PCV valve, http://www.carpartsdiscount.com/auto/parts/2002/pontiac/gran d_prix/pcv_system/pcv_valve_kit.html?3593=260504 (i had an 01 GT from 46,560 to 206,980 meaning i personally drove it 156,420 miles)