I just replaced the head gaskets on an 04 i also installed new injectors in this truck. Have a #5 high circuit and also an inbalance code for #5 the plug look fine but still misses on it. Also truck is slow cranking when cold (air still in hpop system maybe) but ran it today and got it to operating temp drove it back in the shop cut it off. 5 min later went to it and it wouldnt start ICP is only showing 340-360 PSI desired is 650. could this still be air in the system or a weak HPOP? I have pretty much come to the conclusion the #5 injector is just not going to fire but this not starting at all im not sure of. Any help would be great. Thanks.