I had a similiar problem. Could not open the door from the outside. Had to replace a little plastic called a outside door handle snap. It connected the rod to the outside handle. Part number for the passenger side door snap 69293-12050. Fixed it for about $6. But it didn't have anything to do with the lock or latch.
96 Sc400 Door Latch
in 92 - 00 Lexus SC300 / SC400
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