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Are the fuel trim numbers + Positive. or - Negative?????
+ numbers indicate the computer is having to Add fuel to compensate for a lean air/fuel ratio. A - number indicates it has to Subtract fuel because on an over fueling problem, causing an overly rich air/fuel ratio.

Its normal for the upstream/before cat converter O2 sensors to switch fast within the range you posted & for the down stream/after cat converter O2 sensors output to remain steady, if the converter is doing its job.

The P0135 code suggests that their is a heater problem with the upstream bank-1 O2 sensor. This will cause the O2 sensor to be slow to heating up & coming online.