replace engine everything work great but the smoke come out light gray on 1996 Lexus LS400

the machenic say have to change the computer is that possible and how much would it cost?

Asked by for the 1996 Lexus LS400
If the engine runs OK but it smokes, I don't think I'd suspect the computer, I'd suspect the oil rings in the engine.
Get a second opinion at a Lexus specialist.
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