New to this forum but not new to the cars. I have a 2000 GTP and just rolled over 150,000 miles on it. I just installed new coolant elbows, Egr valve, pads and rotors, and hub bearings on driver side front. I am not sure if the LIM gasket has ever been replaced with the new metal one. But I Got the #6 misfire code about 2 monthes ago so i replaced the plugs and wires. And just this past weekend i done all the other work listed above. Now i am getting the dreaded P0300 code and the #6 misfire code also. It only throws the code when i go into boost(passing some one on the highway)and while going up hill when the engine is under a good load(like when in overdrive it builds boost when going up hill). so i am thinking maybe the 3/6 coil pack or maybe a vac leak. Greatful for any replies Thanks