A lean fuel mixture can be the result of several things. First, I'm not familiar with the codes that are no longer present, so let me know what they were.
Next, things that can cause a lean mixture include but are not limited to, low fuel pressure, an exhaust leak before the up or downstream oxygen sensors, dirty fuel injectors, and the list goes on.
If your scan tool has a live data setting, check to see what the short-term fuel trims are first and let me know what they are. Also, watch the voltages at each of the oxygen sensors. They should be changing, but they should be within 0.1 and 1.0v.
I attached the description below of the code from my manual. Read through it and let me know if the things mentioned under the "Action in Service" section were related to the prior repairs.
Let me know.
See pics below.
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Friday, November 17th, 2023 AT 10:06 PM