I have a 2011 grand caravan with the 3.6 and 240k miles. I have been trying to chase down a cylinder 5 misfire. It started out intermittently missing at higher rpms, but now it misses every time it gets over 2000 rpm. P0305 is the only code, I have replaced spark plugs, cylinder 5 injector and coil pack. Did a compression test on cylinders 1, 3 & 5 today, 1&3 were both 150psi, but number 5 was 220 psi. I tested each cylinder several times, and got the same numbers each time. Any ideas? I'm thinking something valve train related, causing the #5 exhaust valve to not open. it also has a tick in the top end. I have not had a chance to pull the valve cover off yet. Any ideas?