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When your truck is cold started, it's in "Open Loop" control mode. It's using predetermined fuel air ratios, and using little or no input from the O2 sensors.
Once the truck warms up, it switches to "Closed Loop" control, and starts relying on input from things like the MAF sensor and O2s to determine the proper air/fuel mix. Theoretically this allows more efficient operation (improved fuel economy).
Since it's running fine while operating in Open Loop, and running poorly when in Closed Loop, I'd focus on the sensors that are involved in a/f calculations like the MAF and O2s.
Since you mentioned O2 sensor codes earlier, those are probably the most likely culprit.
Like I said earlier, do basic diagnostic stuff that doesn't require part replacement first (check fuel pressure, check the coil pack, etc). If everything there checks out, start by replacing the O2s. With every detail you provide, it's seeming more and more like faulty O2s are at the very least contributing to your problems, and maybe the only thing wrong here.
Once the truck warms up, it switches to "Closed Loop" control, and starts relying on input from things like the MAF sensor and O2s to determine the proper air/fuel mix. Theoretically this allows more efficient operation (improved fuel economy).
Since it's running fine while operating in Open Loop, and running poorly when in Closed Loop, I'd focus on the sensors that are involved in a/f calculations like the MAF and O2s.
Since you mentioned O2 sensor codes earlier, those are probably the most likely culprit.
Like I said earlier, do basic diagnostic stuff that doesn't require part replacement first (check fuel pressure, check the coil pack, etc). If everything there checks out, start by replacing the O2s. With every detail you provide, it's seeming more and more like faulty O2s are at the very least contributing to your problems, and maybe the only thing wrong here.
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