Step #1 is always reading the codes. I'm not sure why anybody would start trouble-shooting an issue without looking at the codes first. Keep in mind that a code description doesn't tell you exactly what part to replace, but at least points in the direction to start.
All of the codes shown above are likely related.
First code states that the engine is running too cold. Either the engine actually is running too cold due to an issue such as a stuck thermostat (or simply taking too long to warm up because of that), or a bad sensor or wiring is giving the ECM a bad reading and saying it's colder than what it actually is. You also need to look at the short term and long term fuel trims. This is saying if the engine is running lean or really rich. Zero is the ideal number for those, but I'll guess you will see some really large numbers (they can be positive or negative, but would suspect the number is big).
The second code is stating that the engine is not warm enough to go into closed loop mode. Basically what happens is when you first start an engine it runs what is called open loop, meaning the fuel control is based off of preset parameters. The engine has to warm up before the O2 sensors accurately start reporting and begins controlling the fuel ratio based off of how the engine is running. If the engine is never warming up enough (either actual temp or a bad reported temp) it will never switch over to closed loop. If the ECM is controlling fuel based from a bad temp reading it can run really bad.
The third code is a repeat as shows as pending.....simply meaning the first code happened and then stopped, but the issue is happening again.
The fourth code is saying the O2 sensor is responding slowly. Which could be caused by many things and is related to the above codes.
The first thing you need to do is verify the engine temp. A decent scan tool will give you what the ECM is reading as the engine coolant temp. I would also look at the temp gauge on the dash to see what it is stating (though sometimes what the ECM sees and what is displayed on the dash are different....). If the engine eventually gets up to operating temp (200F ish) but is really slow I would suspect a stuck open thermostat. If it gets to operating temps sometimes and then sometimes drops down to cooler I would also suspect the thermostat. The thermostat should open and close as needed to regulate the temperature. If the coolant reading stays steady and real low I would suspect a bad sensor. One condition that is happening is if the ECM thinks the engine is cold it is supplying the fuel strategy of a cold engine, which is essentially like having the choke on. If the truck runs fine when you first start it up, it likes that fuel strategy. But if the engine if warming up but the ECM is still giving it a lot of fuel like having the choke on it will run bad. Do you have a lawnmower or other small engine with a manual choke? You put the choke on to help it start but what happens if you leave the choke on as the engine warms up....it starts running bad.
You need to fix the above condition first before going any further. There are no indications right now of any other issues. Absolutely no reason to change plugs, coils, or any other sensor right now. Sure, there COULD be something else going on but you need to fix the obvious problems first as shown by the codes. Otherwise you are just randomly throwing parts at it. Anybody telling you to replace random parts not even related to the codes is simply guessing.
