Ok so I’m at a loss here. Truck ran fine Monday and Tuesday of this week and went to go start it Wednesday morning and it wouldn’t start. It threw a code P0449 which is the vent valve solenoid. So went out got that part (which it was cracked) replaced it and truck still won’t start. Fuel pump kicks in. You can hear it come on. It’s got spark but no fire. Checked all the fuses and they are all good. Check engine light is still on but the scanner won’t pick up any other codes.
Any advice on where to go next would be helpful. Don’t know if the crank sensor went out or coil packs???
Its got the V8 5.3 motor and flex fuel.

 

Crank sensor should show a code. I'm no expert on flex fuel motors, but might be a good idea to try and reset it by disconnecting the battery, Also you might want to check your fuel pressure.

 

Unhooked the battery and reset it a few time. Went out to try again and it started right up. Ran great then started dinging that there was no oil pressure and to turn off engine. Oil pressure will read normal and then after 15-20 seconds of running it drops and is running like crap now. Checked oil and there is plenty of oil and it’s not knocking or anything.
Check engine light is off and hasn’t thrown a code.
Could the oil pressure sensor be bad now?

 

Don’t depend on the dash gauge for oil pressure - remove the sensor and check it with a mechanical gauge.