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Normally, when the O2 pegs rich, and the engine runs lean, the narrowband is bad. Think about it, what do you trust more? your narrowband, or your wideband? If the narrowband says rich, and the wideband says lean, the engine must be lean right? so the narrowband is bad.
You could have it wired wrong, or there can be an exhaust leak before the wideband, but after the narrowband, and other possiblities. Furthermore, Is the engine in closed loop? When you say the fuel trim does not move, that tells me that the ECU is not adjusting the A/F ratio for closed loop, which puts you in open loop for some reason. Lots of little inconsistencies here.
Just make sure you do a boost leak test before any more diagnostics. Fill the plumbing, including the inlet before the turbo, with 10-15psi and check for leaks. Could be an air leak after the maf, before the turbo.
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