Hello my name is XXXXX XXXXX I will be more than happy to assist you.
The top possiblities are:
Tune up - plugs and wires
Low fuel pressure - Fuel pump going out, clogged injectors, or fuel pressure regular
Vacuum Leak at intake manifold gasket .
Far as where to start will depend on what tools you have.
Do you have a fuel pressure gauge and/or a can of starter fluid
I will have to thing on this one,
The only time the check engine light will flash is when raw fuel is being dumped in to the exhaust.
The only problem is your vehicle is setting P0174 which is a lean fuel code. Which means your truck is not getting enough fuel.
First thing I would do is swap Bank 1 Sensor 1 Oxygen Sensor and Bank 2 Sensor 1 Oxygen Sensor and see if the problem check engine light keeps the same code of changes. See pic below for location.
Yes just let me know tomorrow. make sure you clear the codes out, Then dive it until the light comes back on.