I have been checking everything I can think of and I still can't get it to start. It will almost start but then it also backfires. The CTS is reading properly, EGR is ok, fuel pressure is OK, compression is good, no codes, and injectors are getting a signal. I checked the wires and replaced them because 2 were bad. I also replaced the spark plugs because they were not looking too good. I double checked and the plug wires are in the correct order. It acts like the timing is off. Any suggestions on what to check next.