P0356 indicates a malfunction in the coil circuit. You've already installed a new coil so it's probably that. You need to check the wiring for "coil F" for voltage and ground. You may have a wiring or connector problem. The sparkplug and injector have nothing to do with the circuit the code refers to which is for the coil.
I had the same problem at 68000 replaced coil,spark plugs etc.. turns out it had bad valves common problem with these cars, fixed under warranty they have a 7year ,70,000 mile warranty ,take it to the dealer quick $3500 for rebuilt top end..